Classroom language ecologies are increasingly diverse as a result of mobility, migration, and information technology. In these spaces, interlocutors may draw upon shared linguistic and cultural resources but also bring in others. Prime examples are additional-language (AL) classrooms, where there is a shared target language, but where students may have different first languages from their classmates and teacher. In this chapter, we review empirical research on interaction in multilingual classrooms in approaches such as ethnography, translanguaging, and conversation analysis (CA), and discuss methods and findings in relation to the growing field of intercultural pragmatics (IP). Additionally, we offer an empirical illustration from video ethnography research in multilingual English AL classrooms in Sweden. With a CA approach, we demonstrate how a group of students participating in a vocabulary game manage an instance of diverging understandings of an English word. We show how, in resolving this interactional trouble, participants draw on the target language English and the societal/school language Swedish, and we discuss the observations in light of the IP concepts of salience and common ground. Finally, we argue that classroom studies detailing social actors’ language repertoires by using audiovisual data are essential in advancing our understanding of multilingual AL classrooms.