Understanding the way in which learners differ from one another is of fundamental concern to those involved in second-language acquisition, either as researchers or teachers. This account is the first to review at book length the important research into differences, considering matters such as aptitude, motivation, learner strategies, personality and interaction between learner characteristics and types of instruction.

Chapter 1 Theoretical foundations; Chapter 2 Methodological considerations in ID research; Chapter 3 Language aptitude; Chapter 4 Motivation; Chapter 5 Language learning strategies; Chapter 6 Additional cognitive and affective influences on language learning; Chapter 7 Interactions; Chapter 8 Conclusions and implications;