This chapter offers a critical review of existing research on language teacher classroom discourse and interaction, including how this interaction has changed with the advent of technology-mediated communication (Blanchette, Lang Educ 23:391–407, 2009). The chapter describes the methods of analysis involved in the synthesis. For example, studies between 2010 and 2020 were included, as well as studies in the field of TESOL, and other modern foreign languages, with the sole focus on exploring teacher discourse and/or interaction in language teaching classrooms, the functions of the teacher talk and the implications of this for language learning. This is followed by a discussion of the findings from the review, including outlining the various aims of the studies, the contexts within which the studies take place, and, in particular, highlighting the discourse features and interactional frameworks emerging from the review with a view to offering a well-rounded view of trends in the field.