AbstractThe use of students’ first language (L1) in additional language (L2) instruction has been a recurring theme in language education research. While research has documented the amount of L1 use and its purposes in L2 instruction, little research has investigated the multifaceted motives that influence language choices at the micro level of social activity where language learning takes place. This study contributes new perspectives by exploring the beliefs of teachers and students from two cases of Norwegian use during English lessons, applying video‐stimulated recall in semistructured interviews to elicit reflections about observed language choices in concrete classroom interactions. The findings revealed the complexity of factors influencing language choice in the L2 classroom. First, although teachers agreed on a mainly English ideal, competing beliefs led to varying instructional practices. Second, monolingual ideals were stronger among the students in comparison with their teachers, but these ideals operated alongside an affective dimension of language choice in interactions with the teacher and group work with peers. The study demonstrates how teacher and student beliefs are influenced by macro‐level sociopolitical discourses about multilingualism and indicates that language choice is influenced by such beliefs in combination with more temporary stances and roles.