A consensus exists in applied linguistics that agency and identity are key concepts in understanding teacher development. Although a large body of research has focused on studying language teacher and learner identity and agency separately, less attention has been paid to the relationship of these concepts in individual development. In this contribution, we use an ecological perspective to explore and illustrate the interplay between and development of agency and identity. The participants in the study were primary school teacher students specializing in foreign language pedagogy for younger learners and studying in a CLIL-based teacher education program. The qualitative data were collected through reflective essays focusing on the Finnish student teachers' past, present and future relationships with the English language during different phases of their bachelor's studies.