English-as-second-language instructors should take into account the importance of context for the meaning of language and address the varieties of English that learners will encounter in their daily lives. The principal elements of language variation and their implications for learners are described for the benefit of second language teachers. These elements include register, topic, mode of discourse, speaker-listener relationships, and purpose of communicating. The teaching of notions and functions as rule-governed aspects of language, differences within language varieties, linguistic forms limited to particular domains, and regional or social dialects that learners might encounter in the target language are discussed. Classroom activities are suggested that integrate language variation into the English learning experience and provide the opportunity for contextualized practice. The exercises include dialogs and role playing, real language activities, and a technique for focusing on the differences among dialects. (RW)