The overall aim of the chapter is to contribute to the discussion on how teachers’ facilitation of classroom interaction can be understood in view of mono- and bi-/multilingual norms, and more specifically how teachers relate to, make use of, and strengthen children’s epistemic authority through language competences in the multilingual classroom. The analysis is primarily based on two sets of data. First, teacher interviews which answer to what problems and solutions teachers experience concerning teaching and learning in the multilingual classroom, and how they view their role as facilitator of dialogue and a promoter of agency and hybrid integration in relation to this. Secondly, video-recordings of classroom interaction in selected European localities teachers’ facilitation of dialogue were explored with regard to considering monolingual and bi-/multilingual ideologies and the promotion of hybrid integration. The analysis shows how the monolingual ideology permeates the data material. Students’ multilingual resources are not recognised and valued; consequently, multilingual students’ agency and epistemic authority is hindered. However, there are glimpses of “cracks” where spaces for alternative practices can be developed, in which students can use their full linguistic repertoire, including varying named languages to express their views or ideas beyond the language of instruction, which create potentials for strengthening students’ participation in classroom interactions. The chapter argues that children’s language competences should be integral to understandings of their epistemic authority and calls for further research into how strategies that accomplish this can be developed and transferred across classrooms and localities, with the purpose of strengthening all children’s epistemic authority in education.