Critical Period Hypothesis and Second Language Acquisition

As we all know,there are many factors affecting Second language acquisition,such as age,intelligence,environment,emotion and so on.Age is considered as one of the most important individual factors among all these.The researches about age arevery important to educational policy-making and curriculum-planning.It is believed that children always have superiority in sec-ond language acquisition when compared with adults.This is supported by Lenneberg’s Critical Period Hypothesis.This papertalks about the relationship between age and second language acquisition and after which some teaching suggestion will be given.