This volume does not offer a complex perspective of the L2 lexicon, but rather represents a sustained attempt to answer some very basic questions clustered around the relationship between the L2 mental lexicon and the L1 mental lexicon. It provides a review of L1 and L2 lexical research issues such as similarities and differences between the conditions of L1 and L2 acquisition, the respective roles of forming and meaning in L1 and L2 processing, and the degree of separation/integration between L1 and L2 lexical operations.