Second and additional language acquisition across the lifespan

This chapter focuses on key issues in the use, acquisition, and mental representation of lexis. We begin by addressing central questions about terminology: What is a word? What are lexical phrases? What does and does not constitute formulaic language? What are free and bound morphemes? How does morphology relate to other linguistic subsystems? What are the formal and semantic properties of words? What are the lexical characteristics of words, such as word frequency and orthographic neighbourhoods? In so doing, we emphasize and exemplify the major role of formulaic language in language acquisition and use as well as regional variation at the lexical level. In the final two main sections of the chapter, we focus on (1) L2 vocabulary learning and (2) the bilingual mental lexicon, discussing, in turn, issues such as the incidental-intentional distinction in L2 vocabulary learning and the development of concept mediation over time as part of the bilingual mental lexicon.