How do language teachers position grammar instruction and interaction in their teaching? This study postulated that, in a context where a communicative approach to language teaching is promoted over a structuralist/behaviourist approach, teacher perception of grammar instruction and interaction might be where the tension between the two approaches would surface. Exploration in this scope is relevant in Japan, where it has been twenty years since an action plan to nurture the national communicative skills in English was announced by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) in 2003. The action plan prescribed the incorporation of learner-centred interactive teaching approaches, and the principles of the action plan continue to be enacted in the present Japanese national curriculum standards of junior and senior high schools (MEXT, 2017a; MEXT, 2018). Yet statistics indicate that Japanese students struggle in expressing themselves in writing and speaking (MEXT, 2019; MEXT, 2022). This study focused in on teacher perception on grammar instruction because extant literature suggests that language teachers hold persistent belief in transmitting explicit grammar rules for students’ deductive application, when research indicates that consciously attained explicit knowledge does not equate to language proficiency (Krashen & Terrell, 1983). Furthermore, the current study enquired into teacher views on interaction and bilingualism. Not only must teachers balance grammar instruction with dialogic activities, but their views of students as potential bi-/multilingual speakers might impact how they design a lesson. Based on a constructionist epistemology, relativism ontology, and a theoretical underpinning of Blumer’s (1969) symbolic interactionism, I conducted semi-structured interviews with 11 Japanese junior high school English-language teachers. A thematic analysis (Braun & Clarke, 2022) on the collected data demonstrated that teacher perceptions regarding grammar instruction, interaction, and bi-/multilingualism were varied, depicting fluidity and uncertainty around pedagogical choices among the participant teachers, but a tendency toward communicative language teaching and scepticism toward monolingual instruction. I conclude that more theory-based discussions would lead to teacher confidence in their practice.