Although the lexicon has traditionally been regarded as one of the three essential elements of language learning, the other two being phonology and syntax, it has often been almost ignored, or perhaps more accurately, taken for granted, whereas phonology and especially syntax have received most of the attention of theorists and teachers alike. However, there is now a growing awareness that lexical knowledge is both more complex than it appears and also more fundamental to learners' overall knowledge of a given language than previously thought. The volume under review is a good introduction to the complexities of lexical learning and a valuable guide for those who are interested in doing empirical research in this area.