The document discusses four main theories of language acquisition: imitation/behaviorism, innateness/nativism, cognition, and motherese/input. The key points covered include: - Imitation theory views language learning as a process of reinforcement through stimulus-response and feedback. - Nativism/innateness theory posits that children are born with an innate language acquisition device that allows them to deduce grammar from primary linguistic data. - Universal Grammar proposes…