To help students understand the multilingual conditions of language learning, this module defines multilingualism from different perspectives (number of languages in the world, status of different languages, etc.); presents the patterns of multilingualism in different nations and explains their settings; and describes the multilingual practices obtaining in different contexts. It further presents a historical overview of traditional and contemporary perspectives on L1 and L2 acquisition/learning and draws on perspectives on multilingualism to explain the current paradigm shift from monolingual to multilingual views on language acquisition/learning, and the effects of multilingualism on language learning.