Introduction

This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book specifically relates the Minimalist feature-based theory to learnability issues surrounding normal and pathological L1A, L2A, and language breakdown. It is devoted to the status of the features Definiteness, Specificity, Case, Person, Gender, and Number in non-native and SLI grammars. The book investigates the acquisition of the pretérito-imperfecto contrast in L2 Spanish in relation to the aspectual shifts induced by grammatical markers of aspectuality and discourse-pragmatic cues. It focuses on the "topicalization parameter" which distinguishes Spanish from English. The availability of clitics in the former makes possible a construction, clitic left dislocation, in which the topic element is coindexed with an agreement clitic in the IP. In acquiring Spanish, Valenzuela's English-speaking subjects have to go from a grammar permitting fewer possibilities (a subset grammar) to one that allows more possibilities.