Ernesto Macaro is Emeritus Professor of Applied Linguistics in the Department of Education at the University of Oxford, UK. He was the founding director of the EMI Oxford Research Group (formerly the Centre for Research and Development in English Medium Instruction) in the Department of Education. His research focuses on second language learning strategies and on the interaction between teachers and learners in second language classrooms and in classrooms where English is the medium of instruction. He has published widely on these topics, including in journals such as "Language Teaching," "Modern Language Journal," "Language Learning Journal," "Language Teaching Research" and "International Journal of Bilingual Education and Bilingualism." He is also the author of "English Medium Instruction: Content and Language in Policy and Practice" (2018). Before becoming a teacher educator and researcher, he worked as a language teacher in secondary schools in the UK. His most recent work explores certification programmes for English medium instruction teachers in higher education and the transition from secondary to tertiary English medium instruction programmes.