二语是指除母语外的第二种语言，二语习得(SLA)就是习得除母语外的第二种语言。

　The acquisition of a foreign or subsequent language (a third or fourth language).

SLA is primarily the study of how learners acquire or learn an additional language after they have acquired their first language (L1).

SLA researchers are particularly interested in the causes of the difficulties that adult learners encounter and the methods that may be used to facilitate the acquisition of a second language

Second Language Acquisition (二语习得)

　 Second Language Acquisition ---- formally established itself as a discipline around the 1970s, refers to the systematic study of how one person acquires a second language subsequent to his native language.

 Distinguish second language & foreign language

Connections between first language acquisition and second language acquisition

 The first language study has served as a backcloth for perceiving and understanding new facts about second language learning (Littlewood, 1986).

 SLA is different from first language acquisition.

 Interlanguage

Contrastive analysis (CA) (1960s)

 Positive transfer----facilitate target language learning

 Negative transfer----interfere or hinder target language learning

 It is believed that differences between the native language and the target language would pose difficulties in second/foreign language learning and teaching, e.g.

 *To touch the society .

 *There are more people come to study in the states.

 *I wait you at the gate of the school.

Shortcomings of CA

 The CA was soon found problematic, for many of the predictions of the target language learning difficulty formulated on the basis of contrastive analysis turned out to be either uninformative or inaccurate. Predicted errors did not materialize in learner language while errors did show up that the contrastive analysis had not predicted. “differences” and “difficulties” are not identical concepts.

Error analysis (EA)

 The contrastive approach to learners’ errors has shed new light on people’s attitudes: the errors are significant in telling the teacher what needs to be taught, in telling the researcher how learning proceeds and those errors are a means whereby learners test their hypotheses about the language to be learnt.

 Two main sorts of errors: Interlingual errors & intralingual errors

Interlingual errors

----Interlingual errors mainly result from cross-linguistic interference at different levels such as phonological, lexical, grammatical or discoursal etc. For examples,

a. Substitution of [t] for [W] and [d] for [T]: threetree, thisdis.

b. Shortening of long vowels: sheepship, meetmit

Intralingual errors

----The intralingual errors mainly from faulty or partial learning of the target language, independent of the native language.