In face-to-face spoken interactions, language learners must construct a meaningful message consistent with the L2 grammar, articulate it comprehensibly, and manage the aspects of oral communication that reflect speaker identity, interlocutor identities, and the characteristics of the interactional context. A lack of sociolinguistic competence can lead to a failure to convey formality, politeness, solidarity, friendship, and group membership, and this will negatively affect the communicative outcome. The current chapter examines the social and situational information one conveys through linguistic variants in speech, offering a state-of-the-art account of empirical research, including a discussion of pressing issues in the field, such as the roles of lexical frequency, geographic variation, and language attitudes, as well as the pedagogical implications of this research.