Theories of language acquisition which emphasize the role of imitation, reinforcement, inheritance, and the active involvement of the child himself in the language acquisition process are discussed in this paper. The three major theories are: (1) the behavioristic theory which asserts that children learn their language through imitation of individuals around them; (2) the nativistic theory which argues that language development is determined from within the child rather than by external factors (i.e., language is innate); and (3) the cognitive theory which, like the nativistic theory, suggests that children are born with certain abilities to acquire language but which disagrees as to the nature of these abilities. Sequences of language acquisition are also discussed. (LL)