Teachers and learners can hold differing ideas about language and goals for language learning which are then played out in classroom interactions. Constructions of what counts as language and learning impact on learner engagement and identity and the outcomes of language learning. This study analyses a researcher's account of the learning of Arabic in three different contexts. Data consist of journals, reflective notes and document collection and are analysed using content and thematic analysis. The study found that conflicting views of language impacted on learner engagement and on the identity positions available to learners, especially to background speakers. It argues that the constructions of language and identity positions offered to learners need to be taken into account in language classrooms for language learning and teaching to be effective. (Contains 1 endnote.)