The document discusses language development and acquisition in early childhood. It provides an overview of the theoretical frameworks of language development, including behaviorist and innatist perspectives. The critical period hypothesis posits that the ability to acquire language diminishes after age 12. The document also outlines the stages of language development in early childhood, from babbling to one-word utterances to two-word sentences and early grammar development. Phonological processes that children use to simplify words are also described.