Understanding classroom interactions is a complex process. This article explores what conversation analysis and sociocultural theory of learning can contribute to that process. The exploration is carried out through analyses of interactions between Brian, a five-year-old boy, and Ms Nikora, his teacher, during a nine-hour social studies curriculum unit in a New Zealand classroom. CA and SCT may appear to be strange bedfellows, in that the former concerns itself with language use, while the latter concerns itself with language as mediation, (...) but they turn out to be useful partners. The analyses reveal at least three perspectives from which participants need to be understanding what is going on in classroom interactions in order to participate in them appropriately and learn through them: how people organize conversations, institutional talk, and how teachers and learners jointly construct learning opportunities. (shrink)