社会语言学第十一章作业Second Language Acquisition刘颖 13073080Second language acquisition is a general term which refers to the acquisition of a second language, in contrast with first language acquisition. SLA is also used as a general term to refer to the acquisition of a foreign or subsequent language. Thus, SLA is primarily the study of how learners acquire or learn an additional language after they have acquired their first language. According to Krashen, acquisition refers to the gradual and subconscious development of ability in the first language by using it naturally in daily communicative situations. Learning, however, is defined by Krashen as a conscious process of accumulating knowledge of a second language usually obtained in school settings.But there are some differences between acquisition and learning. According to Krashen, acquisition refers to the gradual and subconscious development of ability in the first language by using it naturally in daily communicative situations. Learning, however, is defined as a conscious process of accumulating knowledge of a second language usually obtained in school settings. A second language, Krashen argues, is more commonly learned but to some degree may also be acquired, depending on the environmental setting and the input received by the second language learner. A rule can be learned before it is internalized, but having learned a rule does not necessarily prevent having to acquire it later. For example, an English language learnermay have learned a rule like the third person singular "-s", but is unable to articulate the correct form in casual and spontaneous conversation because the rule has not yet been acquired. This shows that conscious knowledge of rules does not ensure an immediate guidance for actual performance. Contrastive Analysis was developed in order to identify and predict the areas of learning difficulty. Given this approach, it was hypothesized that second language errors were predominantly the result of negative transfer, or mother tongue interference and second language learning was believed to be a matter of overcoming the differences between first language and second language systems. According to this view, the major task of second language teaching should predominantly be: first, contrast the native and the target language systems and make predictions about the language items that would cause difficulty and the errors that learners were likely to make; then use these predictions in deciding on the type of language items that needed special treatment in teaching and in material development and the type of intensive techniques that would be employed to overcome learning difficulties created by the interference. In practice, the Contrastive Analysis is not effective because a large proportion of grammatical errors could not be explained by mother tongue interference. Errors predicted by contrastive analysis have often not occurred, whereas many actual errors come from overgeneralization instead of negative transfer. Errors, according to the contrastive analysis approach, are negative and had to be overcome or givenup. In fact, errors produced in a learner’s second language utterance may very well be developmental errors and therefore, should not be looked upon simply as a failure to learn the correct form, but as an indication of the actual acquisition process in action. Developmental errors often result from the effort on the part of the learner to construct and test general rules of communication in the target language.Interlanguage consists of a series of interlocking and approximate linguistic systems in-between and yet distinct from the learner’s native and target languages. It represents the learner’s transitional competence moving along a learning continuum stretching from one’s first language competence to the target language competence. As a type of linguistic system in its own right, interlanguage is a product of second language training, mother tongue interference, overgeneralization of the target language rules, and communicative strategies of the learner. In principle, no human brain can store all the words and expressions of a language. What happens is that when processing the language they hear, children construct the grammar and make sense of the expressions according to the grammar. When producing utterances, they follow the internalized grammatical rules. Without the knowledge of the productive rules, it would be impossible for language users to produce and understand an unlimited number of sentences which they have never heard before. Language acquisition is a genetically determined capacity that all humans possess. Although the development of acommunicative system is not unique to human beings, the natural acquisitionof language as a system of highly abstract rules and regulations for creative communication distinguishes humans from all other animal species. In this sense, humans can be said to be predisposed, that is, biologically programmed, to acquire at least one language. Language development can thus be regarded as analogous to other biological developments in human growth and maturation, such as the growth and maturation of one’s limbs and organs. Humans are equipped with the neural prerequisites for language and language use, just as birds are biologically “prewired” to learn the songs oftheir species.At one time, it was widely believed that children learned language by simply imitating the speech of those around them. We now know that this cannot be true, since many utterance types produced by children do not closelyresemble structures found in adult speech. . If children learn their nativetongue by imitating their parents, how can we account for the utterances that are typical of children’s language, such as the plural form "my foots," the past tense forms of” I eated," and the negative construction of “No the sun shining”? It is impossible that children imitate these structures from adults because they are never heard in adult conversations. In addition, Children with speech impairment for neurological or physiological reasons learn the language spoken to them and understand what is said. A more reasonable explanationis that children are attempting to construct and generalize their own grammatical rules.Some young language learners do seem to make selective use of imitation, but they do not blindly mimic adult speech in a parrot fashion, but rather exploit it in very restricted ways to improve their linguistic skills. The point is that imitation plays at best a very minor role in the child’s mastery of langua ge.。