VietTESOL International Convention 2026

The growing role of English as a medium of instruction (EMI) has been repositioning English language teaching (ELT), including an inevitable shift from purely language-focused instruction to the integration of EMI into ELT. This study examines the effectiveness of integrating interdisciplinary content from geography and physics into teaching the topic of "Green Energy" through an empirical study at Hung Vuong Gifted High School in Gia Lai. To investigate the extent to which this integrated approach improves students’ English competence, the study compared the post-test scores of an experimental group and a control group (n = 35 per group). Five-point Likert-scale questionnaires were administered to the experimental group students to assess their attitudes toward the approach. The findings show that students in the experimental group demonstrated a greater ability to use English to discuss the topic in depth; they were able to expand on it (e.g., relating to real-world energy use in Vietnam) and explain it (e.g., describing the mechanism of hydroelectric power). In contrast, the control group used English to express basic and general knowledge limited to the textbook (e.g., types of green energy sources, their benefits and drawbacks). The study also indicates that students in the experimental group preferred the integrated approach over traditional teaching and learning. It is suggested that the integration of EMI into ELT be applied to certain themes to create a more engaging learning environment, which, in turn, simultaneously enhances students' English competence and their access to disciplinary knowledge.