Explore the Effect of a Critical Period on Second Language Acquisition

Critical Hypothesis: The critical period (CP) refers to a specific "fixed" or constant period of time in which the neurological function of an organism is open to external empirical input. Specifically, there are three important points to this concept. Firstly, this developmental period is biologically determined, the beginning, end, and length of the critical period are constant, and this is due to some of the time keeping time independent of what happens during the time window It is the result of the internal clock.

In the studies of primary and secondary languages, the concept of "critical period" of "sensitive period" was established to explain the benefits a child might possess in the process of language acquisition. The purpose of this semester thesis is to investigate whether there is a period sensitive to second language learning and to explore possible interpretation methods. In this research, "critical period hypothesis" (CPH) is the main focus. According to this hypothesis, "Someday, acquisition of language is easy and complete (that is the ability to master a mother tongue), this is difficult and there are many imperfections beyond this period" (ELLIS , 1997: 67). This means that language learners are supposed to have to learn languages ​​since childhood to achieve localized proficiency.

First, we need to clearly state how key periods capture learning of second language. Johnson and Newport (1989) improved the presentation of the hypothesis of the critical period and explained how it interprets the second language acquisition. They distinguish between two further hypotheses, the movement hypothesis and the maturation state hypothesis. They all believe that humans have a strong ability to learn languages ​​at an early stage in their life. These two hypotheses predict that children are superior to adults in learning first language, but only the latter predicts children to be better in second language learning. In fact, the movement hypothesis suggests that adults may be better than children.

The individual learns the second language. In many studies, age is closely related to important time. Regarding mastery of the second language and assumption of the key period, there are many controversial problems. As Singleton (2005) predicted, various CPs such as "the water in mythology, diversity of its head, and the ability to create a new head" can not cope with it (p .288). He announced that a critical period is coming to an end. Some researchers restrict CPs during adolescence and adolescence, but some researchers extend it after puberty. so