1 Introduction:describing and explaining L2acquisition
What is 'second language acquisition'?
What are the goals of SLA?
Two case studies
Methodological issues
Issues in the description of learner language
Issues in the explanation of L2 acquisition
2 The nature of learner language
Errors and error analysis
Developmental patterns
Variability in learner language
Summary
3 Interlanguage
Behaviourist learnig theory
A mentalist theory of language learning
What is 'interlanguage'?
A computational model of L2 acquisition
4 Social aspects of interlanguage
Interlanguage as a stylistic continuum
