Individual differences are believed to be in close connection with second language acquisition (SLA). In this paper, the key age hypothesis is used to review and analyze the learner's starting age, and the learning characteristics and learning conditions of the second language learners of young children, adolescents and adults are studied through comparative analysis. The results show that starting age not only affects the efficiency of second language acquisition, but also affects the proficiency of second language acquisition. Learners at different ages maintain different advantages according to contrastive analysis. Best starting age for SLA is essential to be speculated carefully about the goals of instructional programs and contexts before concluding about necessity of the earliest possible start.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.