1) There are several stages of acquiring a first language from birth to age 12, involving babbling, first words, word combinations, and developing complexity in phonology, syntax, lexicon, and conversational skills.
2) Views of first and second language acquisition include behaviorist, nativist, cognitive-developmental, and social-interactionist perspectives involving imitation, practice, innate abilities, cognitive development, motivation, and social interactions.
3) While first and second language acquisition share similarities through practice and imitation, second language learners are more cognitively developed but learn in a more decontextualized environment compared to first language learners.