Belonging to the ‘Cambridge Approaches to Language Contact’ series, this book is a corpus-based study that examines the developmental characteristics of simultaneously acquiring English and Spanish by two siblings in the first six years of life. Naturally occurring language-production data were collected and analyzed to explore how different degrees of exposure to bilingual performance will impact the emerging grammar of two children.

This book is composed of eight chapters. Chapter 1 is an introduction mainly presenting the eclectic empirical approach to the investigation of bilingual development. In chapter 2 Silva-Corvalán emphasizes the necessity to take ecological differences into consideration when studying language acquisition. Two children's social and bilingual context since birth is described. Approaches to collecting and analyzing language data are also explained. The language data, diary records, and audio recordings of spontaneous speech are analyzed both qualitatively and quantitatively. Chapter 3 presents an overview of how two children attained English and Spanish simultaneously in their first six years of life, showing that their path of developing two languages is similar to that of monolingual children. Chapter 4 examines the developmental path taken by two children while acquiring subjects in two languages, finding that different degrees of exposure to English and Spanish lead to different degrees of acquiring the norms of subject usage in each language. Semantic and pragmatic factors that may influence the acquisition of subject by bilingual children are also analyzed. Chapter 5 discusses the developmental path taken by two children while acquiring subject position in English and Spanish. Due to less exposure to Spanish than English, they show a higher proficiency of using preverbal subject—a characteristic of subject placement in English. Even so, they still stick to semantic and discourse-pragmatic rules while using Spanish utterances. Chapter 6 pays special attention to the developmental characteristics of two children's acquiring English copula be and Spanish copulas ser and estar, revealing that the copula acquisition of both siblings is quite similar to that of monolinguals. Analysis finds no evidence of an effect of Spanish on their acquisition of English be. Chapter 7 studies the acquisition of verb morphology (tense, aspect, and mood), revealing that differences in the development of knowledge of verbs between the two children and monolinguals do not show until age four. Chapter 8 is the concluding chapter where main findings are summarized and important factors that influence bilingual children's acquisition of two languages are emphasized, such as the degree of exposure, input complexity and frequency, cross linguistic interaction, and so on.

This book is a corpus-based study of the developmental characteristics of two bilingual children acquiring English and Spanish. A contrastive analysis is also made between their bilingual output and developmental path and those of monolingual learners. It is a very enlightening book for those interested in language acquisition and developmental linguistics.