Individuals and communities, especially in globalized, super-diverse, and multilingual urban contexts, are often faced with unpredictable linguistic and cultural repertoires in their daily lives. In this local/global context, the second language classroom represents one of the most significant spaces of social interaction and production of meaning for most children and teenagers worldwide. It seems, therefore, essential to discuss classroom interactions considering the teaching process as part of an ideological undertaking that either projects citizens towards passiveness, dependence, and monoculture, or towards change, autonomy, and transculturality. Our chapter discusses the contributions of the interactional sociolinguistics approach to the process of teaching and learning Portuguese in Macau, China, from both theoretical and analytical points of view. We consider the analysis of classroom interactions to argue that different language practices may project (and be projected by) different classroom cultures and identities that give rise to the discourses of individuals and didactic resources for language teaching. The study mainly focuses on the socio-political implications of giving and suppressing voice, agency, and participation in the classroom through different discursive practices. We argue that interactional approaches in the context of language teaching can engender culturally sensitive individuals to act in the world critically and responsibly and fight for linguistic citizenship.