The aim of this study is to investigate the outcomes of teacher educator-initiated action research (AR) process at a teacher education institution in southern Argentina. This process was triggered by a challenge which emerged in the 2016 academic year: how to teach a linguistics module through English to low-level English language users in the first year of a programme designed for teaching English as a foreign language at primary and secondary schools in Argentina. Such a situation became a pedagogical opportunity to engage in AR with a group of student-teachers during a whole academic year. Framed in qualitative research, data collection included journals, teaching and learning artefacts, and interviews. Results show that the integration of content and language learning helped student-teachers develop their language proficiency and strengthen their awareness as language users and future teachers.