二语习得--英语

On Krashen’s Second Language Acquisition TheoriesAbstract : Krashen’s Second Language Acquisition Theories con sist of five main hypothesizes : the acquisition-learning hyp othesis ,the natural order hypothesis ,the monitor hypothesis ,the input hypothesis ,and the affective fliter hypothesis . These hypothesizes have certain directive significance to tea ching practice ,but also has some limitations : ignore the ou tput acquisition process ,lack of operability in actual teach ing in some degree.Key words : acquisition-learning hypothesis , natural order hypothesis , monitor hypothesis ,input hypothesis ,and affect ive fliter hypothesisⅠ.IntroductionAs a part of Second Language Acquisition ,Krashen’s Second La nguage Acquisition Theories is very significant in Second Lan guage Acquisition According to his theories second acquisitio n has two quite different systems : acquisition and learning systems .Acquisition is the subconscious development of langu age rules ,just like in first language development .It focuse s on meaning ,instead of on language form . Learning involves formal knowledge (and teaching ) of a language ,including er ror correction .It is a conscious development of language rules .Krashen argues that error correction and learning does no t lead to acquisition of fluency ,and that acquisition is mor e important than learning .Next we will have detailed analysi s of his hypothesizes .Ⅱ.General Understanding of Krashen’ Second Language Ac quisit ion TheoriesAcquisition-Learning HypothesisThis hypothesis is what Krashen considers to be perhaps the m ost fundamental of all hypothesizes .And it has been highly i nfluential, and still remains the source of much debate today. The starting point ,also the core of this hypothesis is the distinction between acquisition and learning, and the differe nt roles they play in second language acquisition. When learn ers acquire a second language they will internalize the langu age rulesubconsciously .They will not pay much attention to the langu age forms ,but to the meaning they want to express and unders tand. Learning (usually refers to the formal classroom contex t ) is the process of conscious study of language uncover kno wledge ,such as language rules. It is systematical and formal. According to Krashen, only acquired knowledge is readily available for natural fluent communication, and learned knowledg e can only play as a monitor using language.Monitor HypothesisThis hypothesis has a close relationship with acquisition –l earning hypothesis. It states that ,only language acquisition system ,also the potential language knowledge ,is the real k nowledge competence, and that conscious learning has extremel y limited function in adult L2 performance. Acquisition”inna tes “ the speaker’s utterances and is responsible for fluenc y .While learning has only one function –as a monitor or edi tor, making minor changes and polishing what the acquired sys tem has produced .This monitor comes before ,while ,and after the language output (speaking and writing).There are three k inds of monitor users ,monitor over-users ,monitor under user s ,and monitor optimal users. Learners should properly use th is monitor according to their personal situations. While have a conversation with others, we should focus on meaning not l anguage forms. And the conversation will not be fluent if we overuse the monitor. However, while writing it is necessary f or us to use the monitor to avoid expressing faults. There ar e three conditions for us to use monitor：Time (best applied when there is enough time)Focus on form (not on communication)Know the rules.Natural Order HypothesisStudents acquire (not learn) grammatical structures in a pred ictable order, that is certain grammatical structures tend to be learned early and others later. It appears that the order of acquisition for first language acquisition is not identic al for second language acquisition, but there are some simila rities. The naturalorder hypothesis reflects Noma Chomsky’s revolutionary notion that we all have a built-in Language Acquisition Device (LA D).Because of the LAD we tend to learn different language str ucture at different levels/stages as young learners ( also th e same for older learners).Equipped with this innate device , language learning follows a its natural route .For example, w hen children and adults learn English as a second language, t hey will acquire the present continue tense earlier than past tense, and 名词复数 earlier than 名词所有格Input HypothesisAccording to Krashen , the input hypothesis attempts to answe r what is perhaps the most important question in Second Langu age Acquisition filed ,that is ,how we acquire language .Thusthis notion has become the central part of Krashen’s theorie s. The input hypothesis states that one can acquire language in only one way – by exposure to comprehensible input. If th e input contains forms and structures just beyond the learner s’ current level of competence in the language (what Krashen calls i+1).Then both comprehension and acquisition will occur. Input which is either too simple (i + i) or too complex (i + 2/3/4) will not be useful for acquisition.” i” represents l earners’ current language level .1 represents the input that is slightly higher than learners’ current level. Krashen also provide the requirements of the ideal input :first,the input should be comprehensible. Second, it should be sufficient .t hird, it should be interesting and relevant to learners. Affective FilterKrashen believes that comprehensible alone is not sufficient fo r language acquisition. Learners also need to” let that inp ut in “ .The affective filter determines how receptive to com prehensive input a learner is going to be. Learners with high motivation ,high self-confidence ,a good self- image ,and a low level of anxiety are better equipped for success in Secon d Language .Low motivation, ,low self- esteem ,and debilitati ng anxiety can combine to raise “affective filter” and forma “mental block” that prevents comprehensive input from ente ring the individual’s langua ge acquisition device. The hypoth esis is based on the theory of an “affective filter “ which states that successful secondlanguage acquisition depends on the learners’ feeling. Negati ve attitudes are said to act as a filter ,preventing the lear ners from making use of input, and thus hindering success in language learning. So to help students let that input in ,tea chers should try to creat positive atmosphere in language tea ching, try to activate learners’ positive feeling ,like inter est ,good motivation, and attitude and desire to learn by enc ouragement, humanity care ,vivid design of teaching ,extra-cu rricular activities.Ⅲ. ConclusionKrashen’s theories are very significant in that ,first , it m akes a clear distinction between acquisition and learning ,se cond , it emphases the importance of the comprehensibility of the input , and that it should be slightly higher than learn ers’ present level, third , it attaches importance to learner s’ feeling factors, like motivation, interest , anxiety and a ct , and their influence on learners’ acquisition of a second language.。