This document discusses various cognitive factors that influence second language acquisition. It introduces intelligence/multiple intelligences, language aptitude, and language learning strategies as the main cognitive factors. For intelligence, it describes linguistic intelligence and Howard Gardner's theory of multiple intelligences. For language aptitude, it explains John Carroll's definition and the Modern Language Aptitude Test (MLAT). Finally, it discusses language learning strategies like clarification, guessing, and monitoring. The conclusion states that cognitive factors like intelligence, aptitude, and strategies are important determinants of language learning success.