《secondlanguageacquisitionandthecriticalperiod》由会员分享，可在线阅读，更多相关《secondlanguageacquisitionandthecriticalperiod（43页珍藏版）》请在金锄头文库上搜索。
1、Second Language Acquisition and the Critical Period,What we will do today,Introduction to second language acquisitionHow age affects second language acquisition,Second language acquisition: a first look,Classroom learning not the best example of L2 acquisition L2 acquisition is much like L1 acquisit
2、ion Child L2 acquisition is especially like L1 acquisition Adult L2 acquisition diverges in certain ways from L1 acquisition,Classroom learning not the best example of L2 acquisition,Majority of humans speak an L2; few of them learned it in classroom setting. Classroom language instruction is a rela
3、tively recent phenomenon. It usually involves just the beginning stages of acquisition.,A typical language class,3 hours per week30 weeks per year2 years of study 180 total hours of exposure,What can you do in 180 hours?,If you learn 10 words per hour, you will learn 1,800 words in 2 years.Is this a
4、 lot?No. Average 18-year-old knows 60,000 words. 5-year-old knows 13,000!,So,Classroom language learning is worth studying (and worth doing!),But it is just one piece of the larger picture of second language acquisition.,Second language acquisition: a first look,Classroom learning not the best examp
5、le of L2 acquisition L2 acquisition is much like L1 acquisition Child L2 acquisition is especially like L1 acquisition Adult L2 acquisition diverges in certain ways from L1 acquisition,L2 acquisition is much like L1 acquisition,Have to learn words: dog, run, of Typical error:“Cover(wrap) the turkey
6、with aluminum paper.”Have to learn rules: SVO, “add ed to make verb past tense” Typical error:“I taked test yesterday.”,Second language acquisition: a first look,Classroom learning not the best example of L2 acquisition L2 acquisition is much like L1 acquisition Child L2 acquisition is especially li
7、ke L1 acquisition Adult L2 acquisition diverges in certain ways from L1 acquisition,Child L2 acquisition is especially like L1 acquisition,After arriving in a new language environment, younger children will “catch up” within a year or two.They then appear to be indistinguishable from L1 acquirers of
8、 the language.,Second language acquisition: a first look,Classroom learning not the best example of L2 acquisition L2 acquisition is much like L1 acquisition Child L2 acquisition is especially like L1 acquisition Adult L2 acquisition diverges in certain ways from L1 acquisition,Adult L2 acquisition
9、diverges in certain ways from L1 acquisition,PronunciationInflectional morphology (grammatical endings on words): “The boy walks to school.”Subtle semantic distinctions not present in L1: “I saw a cow” vs. “I saw the cow” “El nio corra mucho” vs. “el nio corri mucho”,But many other aspects of adult
10、L2 acquisition work just as you would expect,Adults readily learn:,Words (vocabulary)Word order and many other aspects of syntax: SVO, VSO, SOV, etc.Neko-ga nezumi-o toraeru.cat mouse catch,Effects of age on L2 acquisition,Critical period for L1 acquisition What would a critical period for L2 acquis
11、ition look like? Do we actually find such a critical period? Do late learners ever attain nativelikeness?,Critical period for L1 acquisition,Critical period = “window of opportunity”,Standard evidence for critical period in L1,Young infants are “universal listeners”. Ability declines around age 1.De
12、laying L1 acquisition until after childhood leads to low levels of grammatical development (e.g. Genie).,Effects of age on L2 acquisition,Critical period for L1 acquisition What would a critical period for L2 acquisition look like? Do we actually find such a critical period? Do late learners ever at
13、tain nativelikeness?,What would a critical period for L2 acquisition look like?,What would a critical period for L2 acquisition look like?,“Geometric features” Heightened sensitivity at beginning Clear point where offset (decline) begins Flat period when critical period is over,What would a critical
14、 period for L2 acquisition look like?,“Temporal features” Heightened sensitivity through early childhood Sensitivity bottoms out when full neurocognitive maturity is reached Continued low sensitivity throughout adulthood,Effects of age on L2 acquisition,Critical period for L1 acquisition What would
15、a critical period for L2 acquisition look like? Do we actually find such a critical period? Do late learners ever attain nativelikeness?,Do we actually find such a critical period?,The “classic” study says yes. Johnson & Newport (1989) compared English proficiency of Korean and Chinese immigrants to
16、 U.S. Age of arrival ranged from 3 to 39 Length of residence in U.S. at least 3 years Subjects tested on variety of English structures,Results:,Clear and strong advantage for early arrivals over late arrivals Age of arrival before puberty Performance linearly related to age Age of arrival after puberty Performance low but highly variable Performance unrelated to age,But,Reanalysis of Johnson & Newport suggests that cutoff point is 20, not puberty Birdsong & Molis (2001) got different results:,
