The focus of this collection is on important themes in L2 acquisition, the nature of grammatical systems developed by language learners in L1 acquisition, third language acquisition, and bilingualism and language attrition. The chapters present an interesting mix of theoretical contributions, overview studies, and experimental designs exploring various research questions, such as learnability and access to UG, L1 influence, the nature of initial and endstate grammars, and variability. The linguistic domains investigated are also extremely diverse: morphosyntax, phonology, the lexicon, argument realization, language processing, and interface phenomena. This book, edited and written by McGill University alumni, is intended as a tribute to Lydia White's contribution to the field of generative second language acquisition. The authors present current work on language acquisition which further investigates several themes developed by White's research. Through these state-of-the-art contributions the reader will be able to identify important new directions in which generative language acquisition is developing and expanding.