An all-important step in the life of a child is language development. The topic of language development is both fascinating in itself and illuminating of all cognitive processes. Languages are acquired by healthy children in stages that are fairly well understood. Even before birth, in the womb, a child is acquiring the phonology of their language environment. Lexicon, morphology and syntax, along with phonology, are soon becoming a part of a child’s linguistic knowledge. The trajectory of that acquisition is complex, and the components of language interact with each other. In this class we explore that trajectory. In language development, the role of caretaker involvement is essential. Bilingual environments are healthy, though language acquisition can follow slightly different trajectories and have some intriguing consequences, many for the better. Language acquisition can occur at any age, though older children and adults have certain special challenges. These topics and many others are explored in this course. Language development is perhaps the integral component of human development in all its other characteristics--body and mind.