The document discusses cognitive factors that influence success in second language learning. It identifies three key cognitive factors: intelligence, language aptitude, and language learning strategies. Intelligence refers to mental abilities measured by IQ tests, and may play a stronger role in rule-based language learning than communicative learning. Language aptitude comprises an individual's ability to identify sounds, understand word functions, deduce rules, and memorize words - it is one of the strongest indicators of success. Effective language learners employ helpful strategies like planning, monitoring, and rehearsal. Teachers can support students' development by understanding these cognitive factors and tailoring their instruction accordingly.