Sert, O. (2019). Classroom Interaction and Language Teacher Education. In S. Walsh and S. Mann (Eds) The Routledge Handbook of English Language Teacher Education. London: Routledge, 216-238. This is the author’s pre-publication draft. Information on the final printed version can be found at: https://www.routledge.com/The-Routledge-Handbook-of-English-Language-Teacher- Education-1st-Edition/Walsh-Mann/p/book/9781138961371 Chapter 15 Classroom interaction and language teacher education Olcay Sert Mälardalen University (Sweden) Introduction Language teachers, like other teachers, perform constant multi-tasking in second/foreign/additional language (L2) classrooms while they are teaching. They manage materials, behaviours, content, discourse, and organise and co-construct (with the learners) learning environments at the same time. At the heart of this multi-tasking lies a process of instant decision making: they initiate turns, respond to student utterances, attend to linguistic mistakes within micro-seconds. Such responsive behaviour may become automatic as teachers gain more experience and acquire a level of expertise (not necessarily parallel to age). Successful teachers align their ‘online decision making’ (Walsh, 2011: 220) with the pedagogical goal of the moment. As research in the last two decades has clearly documented, the convergence between pedagogical goals and unfolding classroom interaction (Seedhouse, 2004; Walsh, 2011; Sert, 2015) is perhaps one of the most important means of creating learning opportunities for students.