In this chapter the psycholinguistic aspects of the acquisition and use of a third language will be discussed. For a long time linguists have treated third language learning as a by-product of research on second language learning and acquisition. But nowadays it is known that learning a second language differs in many respects from learning a third language.

This chapter will focus on the development of research on multilingualism, in particular on current approaches taken in studies which have concentrated on the detection of differences between second and third language acquisition (SLA and TLA henceforth). The main areas of research in the fields of TLA and multilingualism, such as the effects of bilingualism on third language learning, will be discussed in more detail. Subsequently the importance of metalinguistic awareness in multilingual proficiency as one of the emerging cognitive factors will be highlighted.

DIFFERENT PERSPECTIVES

The learning and acquisition of a third language has for a long time been subsumed under research on second language learning and acquisition. For instance, Sharwood Smith (1994: 7, italics in original) defined second language in the following way: