Purpose: Research on EMI (English-Medium Instruction) has addressed the extent to which content lecturers speaking in their L1 perform as well as when they lecture in English. In this study a lecturer who gave the same lecture in his L1 (Catalan) and English was observed to examine if and how transitioning from one language to another impacts his…

University lectures are by far the most common method of teaching at Spanish universities. More recently, however, this knowledge transmission has become increasingly interactive. Students' participation and verbal output becomes especially important in classes where the language of instruction is not the students' mother tongue but a second or…