Second language acquisition has to integrate the totality of the SLA process, which includes both the learning of the core syntax of a language and the learning of the lexical items that have to be incorporated into that syntax. But these two domains involve different kinds of learning. Syntax is learnt through a process of implementing a particular set of universal structures, whereas the learning of lexis is characterised by the building up of associations (or connections). Yet these two systems must come together in the creation of a whole linguistic system in the mind of an individual. This book is designed to state the implications of these two paradigms in as clear a way as possible through examples of the research carried out within each paradigm and to examine how they can be made to inter-relate in a way which would enable us to explain better the overall process of SLA.