Educators in immersion contexts who view a policy of strict separation of languages in the classroom as the ideal model for second language acquisition are often reluctant to make connections between the dominant language, the target language and other home languages resulting in missed opportunities for drawing on pupils’ entire linguistic repertoire to foster their learning (Cummins, 2007; Fives and Gill 2015). This presentation considers teachers’ discourses surrounding the place and role of the dominant language (French), the target language (English) and home languages from the perspective of classroom teachers at one French primary school with a school-wide English immersion program. Since the program’s inception in 2011, the one teacher/one language model has been adopted and approximately half the day is spent in each language. Most of the English-medium teachers received training in the US at a French-immersion school where they were strongly discouraged from speaking any language other than the target language to their students and have continued to adopt this practice. The research project promotes principles of co-construction of knowledge and its appropriation, articulating teaching contexts, as well as the empowerment of teachers (Marcel, 2015). Data comprised of semi-structured interviews and their analysis show a teaching team interested in ways of better exploiting the links between the different language repertoires of pupils, while declaring a lack of expertise (Bailly et al., 2020). Filmed observations, stimulated video recall and focus groups sessions collected during a participatory action-research project (May 2018 to July 2019) were then decided upon by the research-practitioner collective to produce new knowledge and engage in new practices. Several themes which emerged during the data analysis are discussed including: teachers’ and pupils’ use of the dominant language as well as the use of children’s other home languages during the different designated times; the role played by teachers with respect to school language policies and teachers’ developing language awareness throughout the project.