This study is concerned with interactional involvement and identity construction in a university seminar comprised of native and non-native English speaking students. Findings reveal that in their classroom interactions, these two groups of students take on and perceive others to take on identities that have little to do with their language status as native or non-native speakers. Moreover, all seminar participants, regardless of their language status, expend a great deal of interactional effort, using a range of interactional resources, to jointly accomplish their tasks. These findings lead to a consideration of NS-NNS classroom interaction as a site for building mutually beneficial collaborations among linguistically and culturally diverse learners with histories of unequal power relationships. They also lead to implications for designing university-level classroom communities where the development of collaborative relationships and feelings of solidarity and affiliation between learners is considered to be an important component of a meaningful and challenging academic learning environment. (Contains 3 notes, 1 table and 8 excerpts.)