Digital Literacy, Ethics and Sustainability in English for Business: An Implicit CLIL Approach in Higher Education

Introduction

The rapid digitalization of business environments has fundamentally changed professional communication practices and generated an unprecedented demand for graduates with integrated linguistic, digital, ethical, and sustainability competencies (Louhiala-Salminen & Kankaanranta, 2012; Zappettini & Kramsch, 2021). In today’s workplace, business communication is increasingly occurring on various digital platforms such as email, video conferencing, instant messaging, and collaborative tools, each with its own language conventions and pragmatic expectations (Bovee & Thill, 2021). Meanwhile, stakeholders are demanding that organizations behave ethically in their communications and show a real commitment to sustainability rather than superficial “greenwashing” (Lyon & Montgomery, 2015).

Digital literacy is defined as the ability to access, evaluate, create, and communicate information effectively using digital technologies, with an understanding of the social and ethical implications of digital practices (Dudeney et al., 2013). In the context of business settings, digital literacy is not only about technical skills but also the ability to communicate effectively across various digital channels, critically assess information available online, and engage responsibly in digital workspaces. Ethical communication is the responsible use of language that is honest, transparent, fair, and respectful of stakeholders (Guffey & Loewy, 2021). In the business context, ethical communication is becoming more and more important because digital communication allows the quick distribution of information that can have a major impact on customers, employees, investors, and the society.

Sustainability is now a strategic priority for modern organizations. Sustainability beyond environmental protection includes economic viability and social responsibility, typically conceptualized within Environmental, Social and Governance (ESG) principles. Therefore, business English education should prepare students to critically understand sustainability discourse and communicate the sustainability initiatives responsibly while avoiding misleading practices such as greenwashing (Lyon & Montgomery, 2015).
These three competencies-digital literacy, ethical awareness, and sustainability communication-are becoming more and more intertwined in contemporary work environments. Thus, teaching business English should not be limited to linguistic competence but should help students to be able to communicate responsibly and professionally in digitally mediated business environments.

These changing professional needs present major challenges for English language education, especially in the area of English for Specific Purposes (ESP). Digital Business is a program developed in Indonesian higher education to prepare graduates to face the business world in the technology era. However, the business English teaching in these programs is often still language-oriented, emphasizing grammatical correctness and general business vocabulary instead of authentic professional communication practices (Widodo, 2016). This incongruity restricts the students’ capacity to transfer linguistic knowledge to actual workplace interactions, therefore undermining the employability aim of vocational higher education (Hyland, 2019).

Content and Language Integrated Learning (CLIL) provides a promising pedagogical framework to fill this gap. CLIL combines the learning of subject content and language learning, helping students to develop communicative competence while acquiring disciplinary knowledge (Coyle et al., 2010). Unlike traditional language-based approaches, CLIL sees language as a vehicle for learning content, rather than as a separate learning objective. Research has shown that CLIL increases learner motivation, cognitive engagement, and the perceived relevance of language study (Dalton-Puffer, 2011; Lasagabaster & Sierra, 2010). Recent systematic reviews also confirm that CLIL implementation in higher education contributes positively to students' disciplinary understanding, language development, collaborative learning, and twenty-first-century competencies. These findings indicate that CLIL is becoming increasingly relevant in Outcome-Based Education (OBE) environments where communication skills are integrated with professional knowledge and authentic workplace practices (Susilawati et al., 2025).

The pedagogical importance of the explicit and implicit approaches is significant within the CLIL paradigm. Explicit CLIL provides discipline courses completely in the foreign language with the secondary aim of language learning. Implicit CLIL, on the other hand, incorporates language objectives into content-based activities, offering scaffolding to support the development of learners’ language skills while keeping the focus on the content (Marsh, 2012). Implicit CLIL is a more accessible and contextually appropriate approach for intermediate competence students who are not majoring in English, such as the digital business undergraduate students in Indonesia, than full English-medium instruction.

Although CLIL is attracting more and more attention worldwide, there is a lack of empirical research on its use in business English settings, especially in Asian higher education (Hüttner et al., 2013). Most of the previous research on CLIL has been conducted in European settings and within traditional academic disciplines, such as science and social sciences (Nikula et al., 2013). Moreover, although these themes of digital communication, ethics and sustainability have been addressed separately in the ESP literature, few studies have focused on their integrated implementation under one CLIL umbrella.

This research fills those gaps by investigating the use of implicit CLIL in a business English course in a digital business undergraduate program at Universitas Pancasakti Tegal, Indonesia. The study aims to explore the possibilities of systematic incorporation of digital communication skills, ethical consciousness, and sustainability discourse in Business English teaching, as well as students’ perception and interaction with such incorporation.

This study aims to answer the following three research questions:

RQ1: How does an implicit CLIL approach facilitate the integration of digital literacy, ethical awareness and sustainability principles in English for business teaching to digital business students?

RQ2: How do students perceive and engage with CLIL-based business English learning activities with digital, ethical and sustainability content?

RQ3: To what extent do students’ competencies in platform-specific business communication, ethical reasoning and sustainability-oriented discourse develop in CLIL-based instruction?

Review of the Literature

Business English in English for Specific Purposes (ESP)

Business English is a major branch of English for Specific Purposes (ESP) and is defined by its focus on the specific linguistic and communicative needs of business practitioners and students preparing for business careers (Nickerson, 2015). Hutchinson and Waters (1987) laid the groundwork for the idea that ESP teaching should be needs-based, focusing on the target professional contexts of students rather than their general language ability. This principle contrasts business English sharply with the teaching of general English: general English aims at general communicative competence; business English aims at the specific genres, registers and pragmatic conventions of professional business contexts.

Current business English teaching has moved from earlier form-focused approaches to competence-based frameworks that integrate language skills and professional practices (Hyland, 2019). This change is due to the recognition that effective business communication needs not only linguistic accuracy but also genre awareness, pragmatic appropriateness, and intercultural competence (Baker, 2015). Genre analysis, the study of the structural and linguistic features of business texts such as emails, reports, and presentations, has become a crucial component in the design of business English curricula, allowing students to understand how language operates in particular professional contexts (Bhatia, 2014).

There are still challenges for business English education, especially in the non-English major programs. As Basturkmen (2010) notes, a common disconnect between language and content instruction occurs when business English courses are taught by language specialists who are not business experts, thus producing decontextualized language practice that does not integrate students’ disciplinary knowledge. This disconnect is especially problematic within specialized programs like digital business, where professional communication is becoming increasingly mediated by technology and platform-specific conventions not necessarily addressed within traditional business English curricula.

Digital Business Communication: Platforms, Conventions, and Pedagogical Implications

The digital transformation of business has fundamentally changed the way professionals communicate. In addition to email, which was at one point the dominant digital medium, the world now also has video conferencing platforms (e.g., Zoom, Microsoft Teams), instant messaging applications (e.g., Slack, WhatsApp Business), project management tools (e.g., Asana, Trello), and social media platforms used for professional networking and corporate communication (LinkedIn, Twitter) (Bovee & Thill, 2021). Each platform has its own specific conventions of formality, message structure, expectations around responses, and multimodal communication (Byron, 2008).

Research on digital business communication identifies a number of pedagogical challenges. Secondly, the lack of nonverbal cues in text-based digital communication leads to a higher risk of pragmatic failure and misinterpretation (Darics, 2014). To compensate for the lack of contextual information, professionals should be more aware of tone, politeness strategies, and clarity. Second, the speed and informality of platforms such as instant messaging may be at odds with traditional business communication norms, and communicators must balance efficiency with professionalism (Gimenez, 2014). Third, the persistence and replicability of digital communication (messages can be forwarded, screenshotted, and archived) raises the ethical stakes of professional communication, as careless or inappropriate messages can have long-term reputational consequences (Guffey & Loewy, 2021).

Integrating real digital communication practices into business English instruction offers both opportunities and challenges for pedagogy. Authenticity increases relevance and transferability as students are using the real communication tools they will use in their professional lives (Hyland, 2019). However, educators must balance the development of technological skills with linguistic and pragmatic instruction so that students can not only use platforms but communicate within them. In addition, the rapid development of digital platforms presents a moving target for curriculum design, requiring pedagogical approaches that are flexible enough to develop transferable communication principles rather than platform-specific technical skills (Dudeney et al., 2013).

Communication Ethics and Sustainability Discourse in the Business Context

Ethical communication has long been recognized as a cornerstone of professional conduct, including the principles of honesty, transparency, accountability, and respect for diverse stakeholders (Guffey & Loewy, 2021). Ethical communication challenges occur in many areas in business: honest representation of products and services, honest disclosure of risks and limitations, responsible use of persuasion, and fair treatment of stakeholders (Bovee & Thill, 2021).

Sustainability communication is a modern development of business ethics and is concerned with the ways in which organizations communicate about environmental, social, and governance (ESG) issues (Ihlen & Roper, 2014). Stakeholders are increasingly demanding corporate sustainability, which has led to new genres of communication: sustainability reports, ESG disclosures, and carbon footprint statements that students of business English need to understand (Whelan et al., 2013). But sustainability communication is fraught with ethical pitfalls, the most prominent being "greenwashing": the practice of exaggerating or inventing environmental credentials for reputational gain without real change (Lyon & Montgomery, 2015).

The critical discourse analysis of corporate sustainability communication uncovers the typical linguistic strategies utilized in greenwashing: vague quantifiers (e.g., “eco-friendly,” “green”); claims without supporting evidence; selective disclosure highlighting positive features and concealing negative impacts; visual rhetoric establishing deceptive environmental associations (Schmuck et al., 2018). To develop ethically responsible business communicators, it is important to teach students to identify and analyze these practices.

Ethics and sustainability are important facets of modern business but are still on the periphery of much business English education. Hyland (2019) notes that ESP teaching often emphasizes linguistic forms and genre conventions to the neglect of the critical dimension of communication, such as power relations, ethical issues, and social consequences of language use. This gap can be filled through the infusion of ethical and sustainability content into business English teaching to promote students’ critical awareness and professional responsibility (Benesch, 2001).

Content and Language Integrated Learning: Theoretical Foundations and Applications in Higher Education

Content and Language Integrated Learning (CLIL) is a pedagogical approach that integrates teaching subject content with foreign language learning that emerged in European education in the 1990s (Coyle et al., 2010). CLIL is based on sociocultural theories of learning and, in particular, on Vygotsky’s (1978) view of language as a mediating tool in cognitive development. From this perspective, language acquisition is most successful when situated in meaningful content-based activities that require learners to use language as a tool for thinking, rather than as an object of study in isolation (Lantolf & Thorne, 2006).

Coyle et al. (2010) introduce CLIL with the “4Cs Framework”, which integrates four dimensions:

• Content: Knowledge and skills of the subject matter
• Communication: language to access content and show understanding
• Cognition: Thinking processes and cognitive skills developed through interaction with content
• Culture: Awareness of Intercultural and Different Perspectives

This framework views CLIL as more than just teaching content in a foreign language; it is seen as a holistic approach that simultaneously develops learners' cognitive abilities, communicative competence and intercultural awareness.

There are many advantages of CLIL, as shown by empirical research. Meta-analyses indicate that CLIL students tend to outperform traditional language learners in receptive skills (listening and reading) but attain similar levels in productive skills (speaking and writing), along with gaining content knowledge (Dalton-Puffer, 2011). Furthermore, CLIL increases learner motivation by improving the perceived relevance and authenticity of language use (Lasagabaster & Sierra, 2010). Students have reported that the use of language to learn meaningful content makes the language study more purposeful than the isolated grammar and vocabulary practice (Coyle et al., 2010).

The distinction between explicit and implicit is relevant for the design of curriculum within the context of CLIL pedagogy. In the case of explicit CLIL, courses in a subject area are taught entirely in the target language, with the primary goal being the learning of content and the secondary goal being the learning of language (Marsh, 2012). The model, which is widespread in European international schools and English-medium instruction (EMI) programs in Asia, presupposes relatively high student language proficiency. However, implicit CLIL embeds language learning objectives within content-based activities, providing explicit linguistic scaffolding while keeping content comprehension as the primary focus (Dalton-Puffer, 2011). The implicit CLIL approach is especially suitable for intermediate-level learners who need structured language support to access content successfully.

CLIL is a growing phenomenon in the world, but there is very little research on its application to higher education contexts, in particular ESP. Most CLIL research focuses on primary and secondary education in Europe (Pérez-Cañado, 2012). Research on CLIL in Asia is increasing but is still under-represented (Tsui & Tollefson, 2007). In addition, CLIL has been applied in science, social studies and humanities subjects but its application in professional and vocational education, including business English, is less documented (Hüttner et al., 2013). Recent reviews indicate that CLIL implementation in higher education continues to expand beyond traditional bilingual education into ESP, business, engineering, and professional education. Current evidence demonstrates that CLIL contributes to improved learner engagement, interdisciplinary learning, critical thinking, and authentic communication while supporting the integration of professional competencies required in contemporary workplaces (Susilawati et al., 2025).

Conceptual Framework and Research Gap

Previous research has looked at business English, digital literacy, ethics, sustainability and CLIL as separate areas of study, but few have examined their combined application within a single pedagogical framework. Existing business English research has tended to focus on linguistic features and genre conventions (Bhatia, 2014; Hyland, 2019) but has not considered digital platform specificity, ethical dimensions, or sustainability discourse. While research on digital communication emphasizes technological affordances and platform conventions (Darics, 2014; Gimenez, 2014), it rarely connects these to language pedagogy. Research on ethics and sustainability in the field of business communication is generally divorced from language education (Ihlen & Roper, 2014; Lyon & Montgomery, 2015). CLIL research has shown its effectiveness in a variety of subjects, but there is a lack of empirical work in Business English contexts, especially in Asian higher education (Nikula et al., 2013).

This study aims to fill these gaps by exploring the potential of implicit CLIL to integrate digital communication skills, awareness of ethics and sustainability discourse into business English instruction for students of a digital business study program.

Methodology

Research Methodology

This study employed a qualitative case study design based on Yin’s (2018) methodology to investigate CLIL-based business English instruction in depth and in its real-world context. The case study method is suitable when the researcher wants to understand the ‘how’ and ‘why’ questions of contemporary phenomena over which the researcher has little control (Yin, 2018). The case study examines the application of implicit CLIL in a Business English course for second-year undergraduate students in the Digital Business program at Universitas Pancasakti Tegal.

Specifically, this study adopted an instrumental case study (Stake, 1995). The case was not selected because it was unique but rather as a tool to understand how CLIL can integrate digital communication, ethical awareness, and sustainability literacy within ESP teaching in a business English course, with the implementation of implicit CLIL. This approach enabled the in-depth study of students’ learning experiences and instructional processes in their real educational setting. The instrumental case study was selected because the intent of the research was to understand how CLIL was being implemented rather than to describe a single classroom on its own.

This study falls under the interpretivist paradigm, which assumes that reality is socially constructed and that understanding requires interpretation of participants’ perspectives and experiences (Merriam & Tisdell, 2015). This philosophical position is congruent with the goal of the study, which is to understand students’ perceptions and learning processes and not to measure learning outcomes quantitatively.

The case study design employed multiple sources of data to allow for triangulation and to enhance the study’s credibility (Stake, 1995): instructional materials, student assignments, reflective journals, instructor field notes, and final projects. The multi-source approach allowed for cross-verification of findings and better understanding of the phenomenon from different perspectives.

Research Background

Institutional Context

Universitas Pancasakti Tegal is a private university in Tegal, Central Java, Indonesia. It has around 6,000 undergraduate students in various faculties. The digital business study program was launched in 2020 to prepare graduates for success in technology-driven business environments, including courses in business administration, digital marketing, e-commerce, and data analytics.

Business English is a mandatory two-credit course that is offered in the second year (fourth semester) of the digital business study program. The course is taught twice a week in a 14-week semester, with 90-minute sessions adding up to 42 contact hours. Students have studied one semester of General English before this course, which gives them basic grammar and vocabulary. Business English is a prerequisite for subsequent courses such as international business communication and business correspondence.

Participants

The participants were 42 second-year undergraduate students (24 female, 18 male) who were enrolled in the Business English course in the second year of 2025. Ages ranged from 19 to 21 years (M = 19.8, SD = .6). All participants were Indonesian L1 speakers learning English as a foreign language.

All students were assessed as having intermediate proficiency (B1 level of the Common European Framework of Reference for Languages) by an institutional placement test taken at course entry. Students had prior experience with digital communication tools (email, instant messaging, and video conferencing) for personal and academic purposes; however, they had limited experience in professional business communication contexts.

Purposive sampling was used to select participants who would provide rich information about the phenomenon being studied. Participants were students enrolled in the Business English course where the implicit CLIL approach was implemented. As the case was bound to one naturally occurring class, all 42 students who met the inclusion criteria were invited to participate. The study was approved by the university's research ethics committee (Approval #2025-ETH-098).

Table 1. Participant Characteristics

Instructional Design: Making Implicit CLIL Work

The business English course was redesigned by means of an implicit CLIL approach to integrate digital communication, ethical awareness, and sustainability literacy. The difference between explicit CLIL, in which the content courses are completely taught in English, and implicit CLIL is that the latter incorporates language learning objectives into the content activities and offers explicit linguistic scaffolding (Marsh, 2012).

Implementation of CLIL

The implicit CLIL approach was implemented via four main features:

1. Content-driven topics: all topics for the courses were derived from the content of digital business courses (digital marketing communication, e-commerce customer service, corporate social responsibility reporting, data-driven business communication), thus ensuring disciplinary relevance.
2. Integrated language objectives: language learning objectives (e.g. formal email conventions, hedging for ethical critique, passive voice in sustainability reports) were integrated into content tasks rather than taught separately.
3. Scaffolding strategies: linguistic supports provided:
4. Business-related vocabulary glossaries for pre-task purposes,
5. Model texts illustrating target genres,
6. Language frames and sentence starters for productive activity, and
7. Teaching of conventions specific to the platform directly.
8. Authentic materials: we provided authentic business texts, such as corporate emails, sustainability reports, and marketing communications. We also provided simulated professional scenarios that required students to apply their learning in realistic contexts.

Course Architecture

The 14-week course was segmented into four thematic units, each unit combining digital communication, ethics, and sustainability in business English teaching. The course structure is given in Table 2.

Table 2. CLIL Integration and Course Structure

Learning Activities

Learning activities were designed to involve students in authentic communication tasks of the profession:

• Case study analysis: Students analyzed real-life business communication scenarios, identified ethical issues, evaluated effectiveness, and proposed improvements.
• Digital communication projects: Students wrote platform-specific communications (emails, instant messages, and video meeting agendas) for simulated business contexts and received feedback on content and language.
• Reflective journals: Weekly reflective journals were kept by students (submitted via Google Classroom) responding to prompts pertaining to their learning processes, challenges, and insights.
• Collaborative tasks: Team projects that utilized digital collaboration tools (Google Docs, Slack) for planning and executing business communication tasks, mirroring workplace teamwork.
• Final integrated project: Students developed an integrated communication strategy for a digital business case, demonstrating integrated competence in platform-specific communication, ethical reasoning, and sustainability awareness.

Data Collection

Data were collected over the 14-week semester using multiple sources to allow for triangulation and a more complete understanding of the phenomenon. Table 3 summarizes the data collection procedures.

Table 3. Matrix for Data Collection

Methods of data collection:

1. Assignments: delivered electronically through the university’s learning management system; downloaded as PDFs for analysis.
2. Reflective journals: weekly reflections to be submitted on Google Classroom based on structured prompts (e.g., “What did you learn about professional email communication this week? What challenges did you face? How does this relate to your future career?”). Prompts changed weekly to correspond with unit content.
3. Field notes: The instructor (researcher) took extensive field notes during and immediately after each class session to document student questions, discussion, observable engagement patterns, challenges, and adjustments to instruction.
4. Final Projects: Students produced digital portfolios containing a written communication strategy, sample communications across different platforms, and reflective commentary on their ethical and sustainability considerations.
5. Data management: All data were stored on a password-protected computer, to which only the researcher had access. Pseudonyms (Student 1, Student 2, etc.) were used to protect the identity of the students during transcription and analysis. Original documents were kept for audit trail purposes.

Data Saturation

Data collection and analysis were conducted simultaneously, consistent with the principles of qualitative case study. Saturation was tracked during the coding process. Students’ reflective journals, assignments, field notes, and final projects were analyzed again, and no substantially new codes or themes arose in the final phases of analysis. The last few reflective journals and projects mainly reaffirmed themes already identified, rather than generating new conceptual insights. Thus, the researchers believed that thematic saturation had been achieved across the multiple data sources. Saturation was assessed according to the redundancy of information across the multiple sources of qualitative data, not the number of participants.

Data Analysis

Data were analyzed using reflexive inductive thematic analysis (Braun & Clarke, 2006). We used an inductive approach because the aim of this study was to allow themes to emerge from the participants’ experiences rather than test a set of pre-determined theoretical categories. While the interpretation was guided by the conceptual framework during the discussion, coding and the development of themes were mainly data-driven.

Analysis Process

Phase 1: Understanding the Data

The data sources were read several times to gain immersion. Reflective journal entries and field notes were read chronologically to understand the temporal progression of learning. First notes and memos were taken to record initial impressions and possible patterns.

Phase 2: Developing Initial Codes

The data were coded line by line using the qualitative analysis software NVivo 12. An inductive coding approach was used where codes emerged from the data rather than being forced into preconceived categories. Different coding methods were applied:

• Descriptive coding: Summarization of factual content (e.g., “describes email structure”)
• In vivo coding: Codes are derived from participants’ own words (e.g., "like text

messages")

• Process coding: Describing actions and behaviors (e.g., “comparing platforms”)

Initial coding resulted in 87 codes across all data sources.

Phase 3: Searching for Themes

Codes were grouped and searched for patterns and relationships to look for possible themes. The connections were investigated using visual mapping techniques (mind maps, code clustering). This process produced fifteen candidate themes.

Phase 4: Define the theme and name it

Candidate themes were compared to coded data extracts to assess internal homogeneity (consistency within themes) and external heterogeneity (distinctiveness between themes). Some themes were merged, others split or removed. The iterative process refined the thematic structure to eight major themes.

Phase 5: Theme Definition and Naming

Each theme was thoroughly examined to determine its essence and limits. They were clearly defined, and themes were named to represent their central meaning. Themes were organized hierarchically with main themes and sub-themes and were aligned with the study’s research questions.

Phase 6: Write the report

The final analysis was concerned with selecting rich, evocative data extracts to illustrate each theme, relating themes to the research questions and literature, and constructing an analytical narrative that moves from description to interpretation.

Inter-coder Reliability

To improve reliability, a second researcher with experience in qualitative analysis independently coded 20% of the data (randomly selected journal entries and assignments). Inter-coder agreement was computed with Cohen’s kappa, which was κ = 0.82, indicating substantial agreement (Landis & Koch, 1977). Discrepancies were resolved by discussion until a consensus was reached.

Reliability

To meet Lincoln and Guba’s (1985) criteria for trustworthiness in qualitative research, we used the following strategies:

Credibility (internal validity)

1. Extended engagement: Full semester immersion in the research setting Triangulation: multiple data sources (materials, assignments, journals, field notes, projects),
2. Member checking: Preliminary findings were presented to five participants who confirmed the accuracy of the interpretations.

Transferability (external validity)

1. Thick description: A rich description of the setting, participants, and procedures enables readers to judge the applicability to their own settings.
2. Reliability (dependability):
3. Audit trail: All data collection, coding process, and analytical decisions are documented, Inter-coder reliability: Verification of coding consistency by a second coder.

Confirmability (objectivity):

1. Reflexive journal: Researcher kept a reflexive journal to document assumptions, biases and reactions,
2. Positionality of the researcher: Discussed below.

Positioning of the Researcher

The researcher is a Business English lecturer with 10 years’ experience in Indonesian higher education who has a doctoral degree in Applied Linguistics with specialization in ESP. The dual role of instructor-as-researcher also raises the possibility of bias, since the researcher has a stake in the results being positive. Strategies to manage this potential bias included reflexive journaling to track assumptions and reactions, member checking to confirm interpretations with participants, and data analysis oriented towards understanding rather than evaluation. The researcher’s insider position had its advantages too: a nuanced understanding of the context, established relationships with students who provided honest answers, and the capacity to document subtle classroom dynamics.

Findings

Three major themes emerged from the data as responses to the study’s research questions:
(1) Development of platform-specific communication competence, (2) Enhanced ethical reasoning and critical awareness, and (3) Cognitive engagement through content-language integration. Below each theme is given with evidence from multiple sources of data.

Theme 1

Developing communicative competence in a specific platform Analysis of student assignments and reflective journals indicated significant growth in students' understanding and application of platform-specific business communication conventions. The theme was categorized into three subthemes: (a) proficiency in email communication, (b) awareness of formality registers across platforms, and (c) pragmatic appropriateness.

Email Communication Competence

Analysis of email assignments submitted at the beginning and end of the semester showed a significant increase in students’ awareness of professional email standards. In Week 3 assignments, 28 students (67%) wrote emails that did not include key features of professional emails:

Draft of Email for Student 7, Week 3:

Subject: Question

hi sir,

hi, can you tell me the price of your product? i want to buy it. Thanks (Ss.1)

This first draft has many issues: a vague subject line, informal greeting (“u” instead of “you”), no context, no professional closing. By week 12, the same student was showing great improvement:

Student 7 week 12 email draft

Subject: Enquiry about product price for bulk purchase

Dear Mr Anderson,

I am writing on behalf of PT Digital Solutions Indonesia to enquire about your pricing for cloud storage. We would like to purchase business licenses for approximately 50 users. Please let me know about your pricing structure for this volume, including any discounts available for annual subscriptions. I would appreciate it if we could get this information back by March 15, 2026, so we can plan our budget.

Thank you for considering this question. I look forward to your reply.

Best wishes, (Ss.2)

Purchasing Officer

PT Digital Solutions Indonesia

This new email shows the writer’s knowledge of professional email conventions: specific and informative subject line; appropriate formal greeting; clear statement of purpose; relevant context and details; polite request phrasing; deadline specification; professional closing; and complete signature block, including title and organization.

This qualitative observation is supported by a quantitative analysis of email assignments. The mean score on a rubric rating five email components (subject line, greeting, body organization, closing, signature) increased from 2.3/5 (SD = 0.8) in week 3 to 4.6/5
(SD = 0.5) in week 12, a statistically significant improvement (paired t-test: t (41) = 18.4,
p < .001, Cohen's d = 3.4, large effect size).

Students’ reflective journals noted their growing awareness of email conventions: “Before I took this course I wrote emails like text messages, very casual and short. I did not know about subject lines or how to structure the body of the email. Now I know that professional emails have a structure and a purpose. Each part has a function” (Student 15, reflective journal, week 11).

“I learned that in emails, formality is important. In Indonesian, we can be more direct, but in English business emails, we have to be polite and use indirect language for requests. This was difficult at first, but now I can do it” (Student 23, reflective journal, week 10).

Recognition of Formality Registers across Platforms

The CLIL-based instruction offered students the chance to utilize diverse digital communication platforms and to cultivate awareness that different platforms necessitate varying degrees of formality and conventions. Analysis of students’ final projects, where students were required to produce communications for email, instant messaging, and video meeting contexts, revealed a sophisticated understanding of register variation. This awareness was made explicit by students in their reflective commentaries: Email is the most formal. We use full sentences, proper greetings, and formal vocabulary. Instant messaging on Slack is faster and more casual; we can use abbreviations and short sentences. But even in instant messaging we have to be professional, not like we are chatting with friends. Video meetings are somewhere in between-we talk more naturally but still use professional language" (Student 31, final project reflection).

Field notes documented classroom discussions in which students discussed the appropriate level of formality:

In week 8’s instant messaging discussion, students debated the appropriateness of emoji in workplace instant messaging. Student 19 argued that emoji help convey tone and prevent misunderstanding, while Student 27 said they are unprofessional. The class ultimately agreed that context matters-emoji might be acceptable in internal team communication but inappropriate in client-facing messages. (Instructor Field Notes, week 8, Session 2). This emergent awareness is indicative of important learning as students moved from undifferentiated digital communication practices (treating all platforms similarly) to nuanced appreciation of platform-specific conventions.

Pragmatic adequacy

In addition to structural conventions, students developed pragmatic competence; that is, they learned to use language appropriately in social contexts. This was particularly evident in the way they dealt with face-threatening acts such as requests, complaints and refusals. Early assignments were direct, possibly face-threatening communication: Student 12, week 3 complaint emails:

“Your product is broken. Send me a new one, now.”

Later in the semester, the same student exhibited sophisticated pragmatic strategies: Student 12, week 12 complaint email:

Dear Customer Service, I am contacting you to report a problem with the product I bought on February 10, 2026 (Order #45678). Sadly, the device has ceased functioning after only two weeks of use. I would appreciate your assistance in resolving this. Can we arrange a replacement or repair? I have attached photographs of the issue. Thank you for taking care of this issue. I will await your response.

In this revision, several pragmatic strategies are used: hedging (“unfortunately”), indirect request forms (“would it be possible”), expression of appreciation, and collaborative problem-solving tone instead of demands. Students’ pragmatic awareness was increased as evidenced by reflective journals:

“I understood that in English business communication, we cannot be too direct. Even when we complain or ask for something, we have to be polite. We use would and could instead of direct orders. This is different from Indonesian where we can be more direct with people we know” (Student 8, reflective journal, week 9).

Theme 2: Improved Ethical Reasoning and Critical Awareness

The infusion of ethical content into the business English instruction enhanced students’ capacity for ethical reasoning and critical analysis of business communication. The theme consisted of two sub-themes: (a) Recognition of principles of ethical communication and (b) Critical analysis of greenwashing and sustainability claims.

Recognizing the Ethical Communication Principles

Students were exposed to ethical dilemmas in business communication through case study analyses and class discussions, and their awareness of ethical principles such as honesty, transparency, and stakeholder respect was developed. Analysis of students’ responses to case studies revealed a progression from surface-level moral judgments to more sophisticated ethical reasoning.

In week 7, students examined a case of selective disclosure in a product marketing email. Initial responses revealed a simple moral categorization:

“This email is wrong because it tricks customers” (Student 4, week 7 case analysis). By Week 11, responses to a similar case of corporate crisis communication showed more sophisticated ethical reasoning:

“This communication is ethically problematic for several reasons. First, it uses vague language (‘some customers may have experienced issues’) that downplays the severity of the problem. Second, it emphasizes the company’s ‘commitment to quality’ without acknowledging specific failures. Third, it fails to provide clear information about remedies available to affected customers. While the company is not explicitly lying, this selective disclosure violates the principle of transparency that stakeholders deserve. A more ethical approach would acknowledge the problem directly, provide specific information, and clearly outline steps being taken to address it” (Student 4, week 11 case analysis). This evolution reflects a progression from binary moral judgement (“lying” vs. “not lying”) to acknowledgement of ethical nuance (selective disclosure, minimization) and the use of ethical principles (transparency, respect for stakeholders).

Reflective journals of the students provided evidence of ethical awareness: “Before this course I thought that business communication was only about selling products and making money. Now I know that how we communicate influences people-customers, employees, communities. We have responsibility to communicate honestly and respect people’s right to accurate information” (Student 29, Reflective journal, week 10).

Critical Review of Greenwashing and Sustainability Statements

The sustainability-focused units (weeks 10-12) developed students’ critical analysis of corporate sustainability communication, particularly in terms of detecting greenwashing tactics. Sophisticated critical awareness was evident in the analysis of student critiques of corporate sustainability reports.

Students identified several greenwashing techniques in actual corporate communication: “This company’s sustainability report is full of vague words like “eco-friendly” and “green” and does not have any specific data. They use pictures of nature and green colours to give an environmental association but if you read closely, there are no actual facts on their carbon emissions or waste reduction. They also talk a lot about one small environmental programme while ignoring their main business activities that are harmful to the environment. This is greenwashing. Trying to be sustainable without any real changes” (Student 18, sustainability report critique, week 11).

This study presents evidence of a number of key skills such as the recognition of vague language, the awareness of visual rhetoric, the identification of selective disclosure, and the understanding of the notion of greenwashing.

In classroom discussions, students expressed the challenge of ethical tensions in sustainability communication. Field notes recorded a particularly fruitful discussion:
“In Week 11, students discussed corporate sustainability reporting, and whether companies that are making real progress but still have impacts on the environment should say something about their efforts or keep quiet until they are perfect. Student 35 argued that it is ethical to be transparent about progress, even if imperfect; whereas Student 22 argued that any positive claims could lead to misinforming stakeholders. This debate showed sophisticated understanding of the complexity of ethical sustainability communication” (Instructor field notes, week 11, session 2).

In the final projects, students demonstrated how they incorporated ethical and sustainability awareness into their communication strategies:

“When designing a communication strategy for this digital business, I considered the ethical and sustainability issues. The email marketing campaign has to be honest about the product features and not use exaggerated claims. The social media posts about the company’s environmental practices have to be supported with specific data and not use greenwashing language. All communications have to respect diverse stakeholders and provide transparent information” (Student 26, final project reflection).

Theme 3: Cognitive Engagement via Content-language Integration

The students’ cognitive engagement in learning was evidenced through deeper processing, higher-order thinking, and higher perceived relevance of English learning using an implicit CLIL approach: a) Meaningful use of language for authentic purposes, b) development of critical thinking skills, and c) increased motivation and perceived relevance: these were the three sub-themes within the theme.

Authentic Language Use for Real Purposes

Students reported consistently that the use of English to access digital business content was more meaningful and purposeful in their language learning than earlier language-focused courses. Reflective journals recorded this perception:

“In general English last year, we learned grammar rules and vocabulary lists, but I didn’t understand why we needed them. In this business English course, we use English to do real business tasks-writing emails, analyzing companies, discussing ethical problems. Now I understand that English is a tool for my future career, not just a school subject” (Student 11, reflective journal, week 8).

“This course is different because we learn English and business together. When we analyse sustainability reports, we learn vocabulary about environment and business, and we also learn how to write professional reports. Everything connects to my major, so it is more interesting and useful” (Student 37, reflective journal, week 12).

The sense of relevance encouraged a more engaged approach to the learning tasks. Field notes recorded sustained attention and active engagement:

“Case study analysis of ethical marketing communication in Week 9 saw students engage in a lively discussion for 35 minutes, far exceeding the usual length of participation. Multiple students referenced concepts from their digital marketing course, showing integration of learning across courses. As time was called, several students expressed disappointment that the discussion was ending and asked to continue next session” (Instructor field notes, week 9, session 1).

Developing Critical Thinking Skills

The CLIL tasks demanded students to employ higher-order thinking processes such as analysis, evaluation and synthesis rather than merely reproduce language forms. Students’ work and reflections showed this cognitive demand.

In case study analyses students were required to identify problems, evaluate alternatives, and give rationale for recommendations: I have looked at this company’s crisis communication and considered three possible ways to respond: (1) apologize right away and say what you’ll do to fix the problem; (2) investigate internally and then tell the public later what you found; (3) say very little but point out how good the company’s record is overall. I think strategy 1 is the best because it shows you are taking responsibility, gives stakeholders the information they need, and follows the rules of ethical communication. This strategy may be risky for the company’s reputation, but it builds trust over the long run better than either hiding the problem or waiting to respond” (Student 14, week 11 case analysis).

This answer demonstrates some of the most important critical thinking skills: analysis (recognizing strategies), evaluation (comparing other options), synthesis (combining ethical principles with strategic considerations), and justification (offering a reasoned argument). Students explicitly acknowledged cognitive growth:

“This course makes me think more deeply. We don’t just memorise words or grammar rules. We have to analyse the situation, make decisions and explain our reasoning. It is harder but more interesting. I feel like I am developing professional thinking skills, not just English skills” (Student 21, Reflective journal, week 13).

Improved Motivation and Relevance Perception

Students consistently said they were more motivated to learn English when it was combined with the digital business content that was relevant to their career goals. End-of-semester reflections showed strongly positive attitudes: “I didn’t like English before this course, I thought it was boring and not useful for my future. But this course changed my mind. Now I understand that English is essential for digital business careers. I want to continue improving my English because I see how I will need it professionally” (Student 5, final reflection).

Quantitative data from end-of-semester questionnaires (administered separately from the present study) complemented the qualitative data. The average response to the question “How relevant do you think this business English course is to your future career compared with previous English courses?” (5-point scale, 1 = not at all relevant, 5 = extremely relevant) was 4.7 (SD = 0.5), with 38 students (90%) indicating “extremely relevant” (5).

The students attributed this increased motivation specifically to the integration of CLIL: “Learning English with real business topics is more interesting. When we analyse sustainability reports or write professional emails, I can see myself doing these things in my future job. This link to my career goals inspires me to work harder and pay attention to details (Student 33, reflective journal, week 14).

Field notes documented observable indicators of engagement such as: regular attendance (average of 95% over the semester compared to 78% in previous general English courses), voluntary participation in discussions, requests for further resources, and extra effort on assignments. For example, Student 24 submitted a week 12 assignment that went beyond the assignment requirements. The student not only provided the required email but also analyzed in detail the alternative phrasing options and their pragmatic effects. When I commented on this additional effort, the student explained, “I’m really interested in this because I want to work in international business, so I want to practice as much as possible” (Instructor field notes, week 12).

Discussion

The results of this study show that implicit CLIL facilitates the integration of digital communication, ethical awareness and sustainability literacy into business English teaching and enhances students’ professional communication competence and engagement. This section discusses these findings in relation to the existing literature, theoretical implications and practical applications.

CLIL as a Basis for Integrating Content and Language in ESP

The effective integration of digital business content with business English learning in this study supports the core principle of CLIL theory, namely that language learning is most effective when embedded in meaningful, content-based activities (Coyle et al., 2010; Dalton-Puffer, 2011). Findings indicate that implicit CLIL can bridge the long-standing gap between language instruction and disciplinary content that has posed a challenge to ESP education (Basturkmen, 2010; Hyland, 2019) by developing students’ platform-specific communication competence, ethical reasoning capacity, and sustainability awareness.

Importantly, students found business English through CLIL to be more relevant and motivating than previous language-focused courses. This is in line with the study by Lasagabaster and Sierra (2010), which shows that CLIL increases learners’ motivation due to the increased authenticity and purpose of language use. Students linked language learning more closely to professional identity and showed greater intrinsic motivation (Dörnyei & Ushioda, 2011) when they used English as a tool to interact with digital business content, rather than as an isolated object of study.

The implicit CLIL approach was used in this study, where language objectives were embedded in content tasks, and students were given explicit linguistic scaffolding. This approach was particularly suitable for intermediate students. Unlike explicit CLIL (where full content instruction is in English), which presumes high language proficiency, implicit CLIL facilitates the gradual development of learners through structured scaffolding (Marsh, 2012). The progression of student writing in e-mail format from an early, structurally-deficient draft to a more sophisticated communication at the end of the semester illustrates how content-based tasks, supported by scaffolding, can facilitate language development.

Digital Communication Competence: from Platform Technicalities to Pragmatic Awareness

The cultivation of platform-specific communication competence among students involves not only technical skills but also pragmatic awareness, that is, knowledge of how language works socially in professional digital contexts. This finding adds to the literature on digital business communication by showing that the pedagogy of digital communication for effective teaching must incorporate not only the mechanics of the platform (how to use email, instant messaging, video conferencing) but also the pragmatic conventions (how to communicate properly and effectively in each platform) (Darics, 2014; Gimenez, 2014). Significant learning means shifting from undifferentiated digital communication practices (treating all platforms the same) to nuanced awareness of the formality registers and conventions specific to each platform. This development addresses an important gap identified by Byron (2008) and Darics (2014): the absence of nonverbal cues in digital communication, which makes the pragmatic requirements higher and calls for a higher level of awareness of tone, politeness and clarity. The CLIL-based instruction provided students with the pragmatic competence needed for professional digital communication by explicitly teaching platform-specific conventions through authentic tasks.

Moreover, the development of students’ pragmatic strategies for face-threatening acts (requests, complaints, refusals) suggests that CLIL-based instruction can foster not only linguistic accuracy but also socio-pragmatic appropriateness (Hyland, 2019). The move from face-threatening, direct communication to the sophisticated use of hedging, indirect forms of requests, and language for collaborative problem-solving reflects a growing understanding of norms in English business communication. This finding implies that the inclusion of pragmatics instruction within the content-based tasks may be more effective than isolated pragmatics lessons, as the students encounter pragmatic challenges in authentic contexts that require immediate application.

Ethical Reasoning and Critical Awareness Communication as a Value-driven Practice

This study adds significantly to the development of students’ ethical reasoning capacity and critical awareness of greenwashing. Although ethics and sustainability are being acknowledged as important in business education, they have been on the periphery of much ESP instruction (Hyland, 2019). The study proves that the introduction of ethical content in Business English learning is possible and helps students’ professional development. It sets communication as a value-laden activity that demands an ethical judgement rather than a mere technical skill.

Developmental theories of moral reasoning (e.g., Rest, 1986) suggest that students’ progression from simple moral categorization (“lying” versus “not lying”) to sophisticated ethical reasoning based on principles of transparency, stakeholder respect, and accountability is expected. The case-based approach used in this study, in which real ethical dilemmas were provided for analysis and justified decision-making, was conducive to higher-order ethical thinking rather than simple memorization of rules. This finding suggests that ESP educators can contribute to the ethical development of students through intentional content integration, responding to the calls for more ethically engaged professional education (Benesch, 2001).

Critical analysis of greenwashing and sustainability claims was instrumental in developing students’ ability to recognize manipulative communication strategies, which in turn contributed to their development as critical consumers and ethical professionals. This critical awareness is particularly important in today’s business environment where stakeholders are increasingly demanding authentic corporate sustainability commitment, not superficial ‘green’ marketing (Lyon & Montgomery, 2015; Schmuck et al., 2018). The course trained students to recognize vague language, unsubstantiated claims, selective disclosure, and misleading visual rhetoric, allowing them to critique others’ communication and produce more ethics-based discourse themselves.

Cognitive Engagement: Content, Communication, and Cognition Interacting

This study presents the synergistic interaction of Coyle et al. (2010) "4Cs" (content, communication, cognition, culture) in CLIL as seen in the increased cognitive engagement, including deep processing, critical thinking, and sustained attention. As students analyzed ethical dilemmas, evaluated sustainability reports, and developed communication strategies, they were simultaneously engaging with disciplinary content, linguistic forms, and higher-order thinking processes. This integration created cognitive demand that fostered deeper learning than would be achieved through content instruction or language instruction alone (Dalton-Puffer, 2011).

Of particular interest is the finding that students explicitly recognized their cognitive development, reporting that CLIL-based tasks required ‘thinking more deeply’ and developing ‘professional thinking skills, not just English skills’. This metacognitive awareness suggests that CLIL may enhance not only cognitive engagement but also metacognitive development – students’ awareness of their own thinking processes (Flavell, 1979). This metacognitive awareness is useful for lifelong learning, as it allows learners to monitor and regulate their own development (Vandergrift & Goh, 2012). The observation that meaningful language use for authentic purposes increased motivation and perceived relevance is consistent with sociocultural theories of learning, which argue that learning is enhanced when embedded in authentic purposeful activity (Lantolf & Thorne, 2006; Vygotsky, 1978). When students used English to access digital business content that mattered to their career goals, language learning became instrumental rather than terminal-an instrument to professional goals rather than an end in itself. The instrumental positioning fostered intrinsic motivation through the creation of a professional identity (Dörnyei & Ushioda, 2011).

Contributions to Theory

The study makes several theoretical contributions to the CLIL, ESP and business communication literatures:

• Conceptual framework for integrated ESP-CLIL: The study provides an empirically validated framework for visualizing the systematic integration of digital communication, ethics and sustainability into business English Teaching via implicit CLIL. This framework translates the theory of CLIL into ESP contexts, and provides a model for educators who wish to design integrated curricula.
• Implicit CLIL in higher education ESP: The majority of CLIL research is based on primary/secondary education and explicit CLIL approaches. This study demonstrates the effectiveness of implicit CLIL in higher education ESP contexts. The findings suggest that implicit CLIL is particularly suited for intermediate-level students in professional courses, providing an alternative to language-centred ESP and full English-medium instruction.
• Expanded conceptualization of business communication competence
• The study adds to business communication literature by revealing that professional communication competence in digital environments comprises not only linguistic accuracy and genre knowledge but also platform-specific pragmatic awareness, ethical reasoning capacity, and critical literacy regarding sustainability discourse. This broader conceptualization has implications for curriculum design in business communication education.
• Integration of critical pedagogy and ESP: The study integrates the traditions of ESP and critical pedagogy by demonstrating the meaningful integration of ethical and sustainability content in ESP instruction. This integration addresses long-standing critiques that ESP is instrumental and does not foster critical awareness (Benesch, 2001), demonstrating that professional communication education can develop practical skills and critical consciousness simultaneously.

Implications for Practice

The findings have some practical implications for business English teachers, curriculum designers and institutions:

For Teachers:

• Use content-based methods instead of teaching business English as a set of unrelated grammar and vocabulary drills, integrate language teaching with authentic business content that is relevant to students’ field of study. Use case studies, authentic texts and simulated professional scenarios.
• Give explicit scaffolding implicit CLIL needs structured language support. Support students’ engagement with content by providing glossaries, model texts, language frames, and explicit instruction about genre conventions.
• Teach platform-specific conventions, not just generic "email writing" or "business writing." Address digital platform pecificity: Show students how professional communication means adjusting language for different digital platforms.
• Integrate ethics and sustainability: Include ethical dilemmas and sustainability-related content in business English teaching. Use real corporate communications as the texts for critical analysis, so that students develop their ethical reasoning alongside their language skills.
• Enhance metacognitive awareness: add activities that require students to express their learning processes, difficulties, and reflections (journals, discussions). This type of metacognitive reflection boosts learning and motivation.

For curriculum developers:

• Align language courses with discipline content: collaborate with discipline faculty to develop business English curricula that align with students' discipline learning and professional preparation.
• Sequence content: organize courses so that there is a progression of difficulty from the most basic genres (email) to the most complex (integrated communication strategies).
• Assess students’ integrated competence through authentic tasks (case analyses, communication projects) rather than decontextualized tests.
• Balance skills development: curriculum should cover linguistic accuracy, genre knowledge, pragmatic competence, ethical awareness, and critical literacy, not just grammar and vocabulary.

For Institutions:

• Support professional development: Provide professional development opportunities for ESP instructors to develop content knowledge in students’ disciplines and expertise in CLIL methodology.
• Create structures for collaboration between language instructors and discipline faculty to support curriculum integration.
• Provide access to authentic resources: ensure access to authentic business texts, digital communication platforms, and technology resources that allow for realistic simulation of professional communication contexts.
• Value innovative pedagogy: award instructors who invest effort in developing integrated, content-based curricula, as opposed to using commercial textbooks and teaching generic business English.

The findings of this study have some practical implications for business English teachers, curriculum developers, and higher education institutions. For business English teachers, instruction should emphasize real business content rather than piecemeal grammar and vocabulary exercises. Teachers are encouraged to use case studies, authentic business texts and workplace simulations in an effort to help students’ link language learning with real professional situations. They should also offer clear language support, through glossaries, model texts, language frames, and explicit instruction in genre conventions. Furthermore, business English courses should include lessons about how communication varies on different digital platforms, such as email, instant messaging, and virtual meetings. Finally, ethics and sustainability should be integrated into classroom activities using authentic business materials, while reflective journals and class discussions should be included to help students monitor their learning and improve their critical thinking.

Business English courses should be aligned with students’ disciplinary content and future professional needs for curriculum developers. The curriculum should present communication tasks in a logical order from simple genres such as emails to more complex professional communication tasks. The assessment should focus on authentic performance, using case analyses, communication projects, and other real-world tasks, rather than relying solely on traditional language tests. Furthermore, the curriculum should promote balanced development of linguistic accuracy, genre knowledge, pragmatic competence, ethical awareness and critical literacy.

Offering professional development opportunities for ESP instructors in higher education institutions may improve their disciplinary knowledge and understanding of CLIL pedagogy. Institutions should also promote collaboration between language instructors and experts in the disciplines to facilitate curriculum integration. In addition, students and teachers should be given access to authentic business resources, digital communication platforms and appropriate technology that mirrors professional workplace practices. Finally, institutions should recognize and support innovative teaching approaches that integrate language learning with disciplinary content, instead of relying solely on commercial textbooks or traditional business English instruction.

Limitations and Alternative Explanations

This study provides useful insights, but there are some limitations to be noted:

• Single case design: This is a qualitative case study and was conducted within one course at one institution; findings are not statistically generalizable to other contexts. Transferability is based on the way readers assess the similarity of this context to their own.
• No control group: without a control group receiving traditional business English, we cannot attribute observed learning definitively to CLIL per se rather than general instruction, maturation, or practice effects. Any good course in business English could have brought improvement in the students.
• Instructor-researcher dual role: the potential for bias exists with the researcher conducting the course. Students may have responded in journals and reflections in socially desirable ways and the researcher may have unconsciously interpreted data in a favorable way. Reflexive journaling, member checking and inter-coder reliability measures were used to reduce the risk of this. Complete objectivity is not possible.
• Self-reported data: Much of the evidence is based on self-reports of students (journals, reflections) rather than objective measures of learning outcomes. Students may think they are developing, but they are not actually getting more competent.
• Short time frame: Study carried out over one semester (14 weeks). Longer-term follow-up would be necessary to assess whether learning persists and transfers to real professional contexts.
• Contextual specificity: Findings are obtained from a certain context-Indonesian digital business students with intermediate English proficiency. We do not know how successful this approach is across different levels of proficiency, disciplines, or cultural contexts.

Other explanations:

• Hawthorne effect: the students may have been more involved and performed better because they knew they were part of a research study.
• Instructor enthusiasm: the enthusiasm of the instructor (researcher) towards the innovative approach might have increased the motivation of the students independently from the CLIL method itself.
• Novelty effect: students' positive reaction may be due to novelty rather than sustainable pedagogical effectiveness.
• Selection bias: students opting for the digital business study program may have had characteristics (motivation, career orientation) that predisposed them to respond positively to professionally relevant instruction.

These limitations and alternative explanations highlight caution in generalizing findings and suggest avenues for future research.

Conclusion

This qualitative case study explored the implementation of implicit Content and Language Integrated Learning (CLIL) in a business English course for digital business students at Universitas Pancasakti Tegal, with particular attention to the incorporation of digital communication, ethical consciousness, and sustainability principles into ESP instruction, and how students perceive and engage with this integration.

The results show the effectiveness of implicit CLIL in relation to the integration of disciplinary content with language learning and the development of students’ professional communication competence in multiple dimensions: platform-specific digital communication skills, capacity for ethical reasoning, critical awareness of the discourse of sustainability and pragmatic appropriateness in business contexts. Also, CLIL-based instruction enhanced students’ cognitive engagement, motivation and perceived relevance of English learning, by positioning language as a vehicle to engage in meaningful professional activity rather than as an isolated educational goal.

This study contributes to CLIL literature by showing the effectiveness of implicit CLIL in higher education ESP contexts; to ESP literature by providing a framework for integrating digital, ethical and sustainability content in business English instruction; and to business communication literature by expanding conceptualizations of professional communication competence to include ethical and critical dimensions alongside linguistic proficiency.

In practical terms, the study offers a pedagogical model for teachers to align business English teaching with the demands of today's workplaces and the professional development of students. These findings point to the possibility that ESP education can and should move beyond language-centric approaches to integrated frameworks that develop students’ disciplinary knowledge, communicative competence, ethical awareness, and critical consciousness at the same time.

Future research should include comparative designs to isolate CLIL effects, longitudinal studies to track long-term learning outcomes and transfer to professional contexts, examine CLIL effectiveness at different proficiency levels and across disciplines, and investigate instructor professional development needs for implementing CLIL-based ESP instruction. Further research in different cultural and institutional contexts would improve understanding of the transferability of CLIL and adaptation needs. In an era of rapid digitalization, heightened ethical scrutiny and urgent sustainability imperatives, business English education must prepare graduates to be linguistically competent, digitally proficient, ethically sensitive and critically aware professional communicators. The findings of this study suggest that implicit CLIL provides a promising pedagogical framework for the attainment of these integrated learning goals.