Young children's natural processes of language acquisition, the ways they learn a second language, and guides for teaching children a second language are discussed. Topics addressed include social influences on language acquisition, code-switching in bilingual communities, and the relationship of enculturation and acculturation to the development of bicultural competence. In addition, children's development of metalinguistic awareness in their second year, the influence of first language acquisition on second language acquisition for children 2 years of age or older, vocabulary acquisition, peer influence on language learning, and children's language use in the context of social interaction are explored. Four hypotheses that have been proposed to account for observed differences in children's ability to become bilingual in educational contexts are reviewed. Concluding sections of the paper offer three basic principles which underlie the teaching of a second language to young children and 10 guidelines for teaching second language learners. Directions for future research are indicated. (Author/RH)