What is SLA?
Second Language Acquisition (SLA) refers both to the study of individuals and groups who are learning a language subsequent to learning their first one as young children, and to the process of learning that language. The additional language is called a second language (L2), even though it may actually be the third, fourth, or tenth to be acquired. It is also commonly called a target language (TL), which refers to any language that is the aim or goal of learning. The scope of SLA includes informal L2 learning that takes place in naturalistic contexts, formal L2 learning that takes place in classrooms, and L2 learning that involves a mixture of these settings and circumstances.
二语习得综述
Second Language Acquisition
*Language learners can study the language as a school subject, consciously learning and memorizing facts about the language. This results in conscious knowledge about the language that is referred to as declarative knowledge陈述性知识or explicit knowledge 隐性知识. Stephen Krashen calls this language learning.
*Language learners can also gradually gain unconscious control over
the language by using it actively for functional and communicative purposes. This results in unconscious knowledge that is referred to as procedural knowledge过程性知识or implicit knowledge显性知识. Stephen Krashen calls this language acquisition.
----二语习得内隐外显学习研究-问题与思考-戴炜栋
语言的本质 Nature of Language
语言现象有生理及心理的基础，同时也是历史及文化的产物。从语言本能（language instinct）的角度来看，人类语言是生理的现象，在表征上及历程上都受到人类生理的限制。这是人类语言共性的最大基础。
二语习得研究历史回顾
第二语言习得研究与其他应用语言学科相比是一个比较年轻的学科。作为一个特定的研究领域，她的发端可以追溯到20世纪60年代末。
Lightbown (1985) 指出，在第二语言习得研究领域，学者们大都把Corder 1967年发表的 ―The significance of leaners‘errors‖ 以及Selinker 1972发表的 ―Interlanguage‖ 这两篇文章看作这个学科建立的标志。
1950 年代，计算机科学的发展，尤其是人工智能（artificial intelligence）的产生，对心理学、语言学及心灵哲学都产生了极大的冲击，导致认知科学的蓬勃发展。The cognitive revolution of the 1950s put forth the idea that there is a mental basis for language.认知科学整合了心理学、心灵哲学、人工智能学、语言学和神经科学。其主要的研究主题为认知行为。这门新兴的科学赋予心智主义（mentalism）新的理论基础，使行为主义（behaviorism）节节败退。就在这个大思潮转弯的酝酿中，Chomsky 把心智主义引进语言学，复燃理性主义，奠定了衍生语法（generative grammar）的哲学基础。Chomsky 进而把语言学研究最高的目标定在对人类心智的了解。从80年代到现在，语言的心理表征（mental representation）、心理历程（mental
process）和习得（acquisition）已经成为认知科学的中心课题。人性及心智发展上的大问题，如先天论与经验论的对立（nativism versus empiricism）或天生与培育的区分（nature versus nurture），也大都围绕着语言的习得及发展。近十年来，在科际整合的潮流中，语言学更与心理学、生理学、心灵哲学和信息科学发生紧密的关系。
第二语言习得思想学派
表1.1所列各种学派是Kuhn (1970)所描述科学革命性的架构的代表。
对比分析(Lado) ?错误分析(Coder)? Chomsky’s LAD &Selinker’s Interlanguage?
20世纪80年代，第二语言习得研究逐渐发展成为一个独立的学科。 Ellis (1994) 对L2的理论发展了概括：
（1）第二语言习得研究的范围越来越广阔。最初的研究主要集中在学习者语言系统的语法特征方面。后来的研究从社会语言学的角度扩展到学习者语言系统的语用方面的研究。
（2）第二语言习得研究的学者们更加关注语言学理论。最为明显的是，许多第二语言习得研究建立在乔姆斯基普遍语法理论模式的基础之上。有些研究则建立在语言功能模式以及语言类型学的基础之上。
（3）以理论为导向的研究越来越多。早期的研究大都是从描写到理论，现在大多数研究则是通过实验检验既有的理论假设。
Ellis关于第二语言习得研究理论发展的概括简要地描述了第二语言习得研究理论发展的轨迹。
*A brief history of the field: 1950s
Theorizing about SLA belonged mainly to the domain of language pedagogy, but was also influenced by the behaviorist paradigm行为主义范式 in the field of psychology.
行为主义心理学认为, 学习是一种行为形成的过程, 语言行为是由―刺激—反应‖构成的。这种理论强调,语言是一种人类行为, 而不是一种思维现象, 语言的发展被描述成一系列习惯的养成。同期对语言学习理论产生重大影响的还有结构主义语言学, 这一语言学流派认为, 所有人类的语言都是有层次的, 层次性是语言的本质属性之一, 语言学应着重研究语言的结构和形式。One well-known linguist who applied the behaviourist theory to the study of language was Leonard Bloomfield, who argued that \analogy permits a speaker to utter speech-forms which he has not heard\
Behaviourism gave birth to a stimulus-response (S-R) theory which sees language as a set of structures and acquisition as a matter of habit formation. Ignoring any internal mechanisms, it takes into account the linguistic environment and the stimuli it produces. Learning is an observable behaviour which is automatically acquired by means of stimulus and response in the form of mechanical repetition. Thus, to acquire a language is to acquire automatic linguistic habits. According to Johnson (2004:18), “[B]ehaviorism undermined the role of mental processes and viewed learning as the ability to inductively discover patterns of rule-governed behavior from the examples provided to the learner by his or her environment”. Larsen-Freeman and Long (1991:266) consider that S-R models offer “little promises as explanations of SLA, except for perhaps
pronunciation and the rote-memorization of formulae”.
This view of language learning gave birth to research on contrastive analysis, especially error analysis, the main focus of which is the interference of one‘s first language in the target language. An important reaction to behaviourism was the interlanguage studies, as the simple comparison between first and second language neither explained nor described the language produced by SL learners. Interlanguage studies will be present in other SLA perspectives, as the concern of the area has been mainly with the acquisition of grammatical morphemes or specific language structures. More
行为主义心理学和结构主义语言学的有机结合催生了影响深远的对比分析学说。
一般认为, Lado 的《跨文化语言学》( 1957) 是第一部探讨具体的对比分析方法的着作。Lado把外语学习的主要困难归于母语与目的语的差异, 认为通过对比两种结构的异同可以预测外语学习者的语言错误和难点。Lee (1968)进一步发展了这一假设, 他甚至认为外语学习中的困难和错误主要甚至全部来自于母语的干扰-母语的负迁移。
*A brief history of the field: 1960s
The fields of linguistics and psychology underwent radical shifts. Behaviorism fell out of favor, and mentalism心智主义 became the predominant paradigm in linguistics.
The field of SLA is often thought to have begun with the publication of an article article by Corder (1967) on learner language. More Corder’s seminal paper \Significance of Learner’s Errors\(1967) had shifted researchers’ attention from the teaching perspective to the learning perspective – and therefore also away from contrastive analysis, behaviorism and structuralism towards cognitive psychology. 以乔姆斯基为代表的心灵学派认为, 行为主义学习理论借助实验室条件下的动物的学习行为来解释人类在自然条件下的语言学习是毫无意义。―刺激——— 反应‖的理论无法解释人类语言学习的复杂性, 模仿与强化的概念也无法说明人类语言学的创造性。
60 年代后期至70 年代初人们便把研究兴趣和重点转移到对二语习得者的语言错误本身的分析。
语言错误可分为两大类: 一类是由于受母语影响造成的错误, 另一类则是二语习得者不受母语影响而出现的错误。这两类错误还可分为: 语言使用过程中的偶然的和随机性错误(mistakes) 和反映学习者过渡性语言能力但具有规律性的错误(error)。对教师来说, 错误是教学中的一种重要的信息来源, 错误分析是教学中的一个重要手段。错误分析可以使教师了解学习者已经具有的语言水平, 从而推断学习者还必须学哪些内容。此外, 我们还可以通过学习者的语言错误了解语言到底是如何学会的,如学习者所使用过的学习策略和程序等。这