Chomsky: Language Acquisition Device (humans are naturally endowed to acquire language)
Critical period: first few years is critical for grammar; second language is best learned before teenage
Phonemes: smallest units of sound
Morphemes: smallest units of meaning
Grammar: includes Syntax, i.e. how to structure a sentences properly; and Semantics, how meanings are made
Cooing: vowel sounds - babies first sounds, 2 months ("Ah", "Oh")
Babbling: 4-6 months ("Ba", "Da")
Holophrase (one-word stage): 1 year ("Go!", "No!")
Telegraphic speech: 2 year - verb + noun ("get bottle")
Overgeneralization/Overregulation: apply grammar rules without making proper exceptions (replace "ran" with "runned", or "fish" with "fishes")