This study explores the effects of teacher feedback on engineering students’ perceptions of learning a business subject and English development in the context of English-medium instruction (EMI). Using a mixed method, it examines specific contributions of teachers’ extensive feedback to the students’ emerging perceptions of interdisciplinary education and EMI. The quantitative section includes questionnaire responses of two groups of students enrolled in four sections of an entrepreneurship course: the control group (CG) in which the students received limited feedback in the lecture-style EMI (n=137) and the experimental group (EG) of extensive corrective feedback (n=133). These results are cross-examined by a semi-structured focus group interview with four respondents. The analysis shows that the university seniors’ mean satisfaction score with EMI, despite staying around the mid-point, was higher than that of the others, and significantly more so than the freshmen group. Notably, EG students appreciated EMI more than CG students. Subsequent findings establish that extensive feedback correlates with the increased positivity towards learning entrepreneurship and, more importantly, English development. This study thus proposes English programs for specific purposes and a support system including an EMI-specialized teaching methodology.