Language experiences and linguistic knowledge of teenage migrants can be valuable resources for their continued language learning. Yet, home languages and existing plurilingual skills are often framed as obstacles to learning that tag young migrants as at risk of school failure in the context of monolingual education systems. This article draws on a comparative education study carried out in Aotearoa New Zealand and France in 2017-2019, observing young migrants' use of their languages in classroom learning. A total of 42 secondary students from a mix of asylum-seeker, refugee, and migrant backgrounds participated, originating from 22 different countries and speaking 24 different languages. All of the students were in their first year of schooling in New Zealand or France at the time of the study. Findings draw on observations of how students made use of their existing knowledge of languages to (1) access learning in the language-of-schooling, (2) learn interactively through their home languages, and (3) navigate unfamiliar styles of teaching and learning, thus engaging with the unknown and developing behaviours for successful learning. Patterns across the cohort show that young migrants are adept at drawing on their existing language resources in learning. This suggests a re-framing of success at school as not only outcomes, but also as defined by effective learning processes that young migrants put in place. As a result, this study suggests ways that teachers can work inclusively with young migrants through their languages, to support processes of learning that could lead to better educational outcomes.