Given the recent surge in interest in bilingualism in general and child bilingualism in particular, the publication of this book is timely as it deals with the development of bilingual competence and bilingual proficiency in children. The terms competence and proficiency, used interchangeably within common usage, are clearly distinguished here. Competence refers to knowledge, whereas proficiency refers to one’s ability to put knowledge to use for comprehension and expression. In relation to bilingual children, proficiency is skill in performance or ability “to use one or the other language that they know, or even both together, for some meaningful purpose” (p. 3). Bilingual competence, although distinct from bilingual proficiency, is viewed as an integral component of bilingual proficiency and refers to the cognitive systems or knowledge structures that underlie it.

An overarching goal, which forms the backdrop to the book’s developmental approach to the study of bilingual proficiency and connects the 10 chapters as a coherent whole, is to significantly advance our understanding of the different kinds of competence underlying bilingual proficiency that interact together to make up its component parts. In examining the relationship between bilingual competence and bilingual proficiency in children, the book’s focus is on the school context. Specifically, it explores the linguistic challenges or problems experienced by children when using two languages for academic purposes, especially in relation to learning to read and write.

As stated in the introduction (chapter 1), two parallel threads run through the book’s discussion of key issues in bilingualism. One thread is a comprehensive assessment of research on the theoretical aspects of bilingualism, including modularity, the poverty-of-stimulus problem, and the relationship between competence and proficiency. A second thread discusses the findings of a long-term investigation of the literacy-related bilingual abilities of children in an indigenous, dual-language-speaking community in Mexico, where Nahuatl (the indigenous language) and Spanish (the national language) are a part of the children’s world. This special sociolinguistic context provides unique insights into the key aspects of bilingualism. In particular, the bilingual indigenous project successfully demonstrates how modularity, the competence-proficiency distinction, and a componential view of bilingual proficiency can help address problems of language learning and literacy. Chapter 2, on bilingualism in school, examines key principles for understanding bilingual and second language (L2) learning in multilingual and multicultural educational settings from a global perspective. It prepares the reader for the exploration of the nature of bilingual language proficiency within the local context of the Nahuatl-Spanish-speaking community in Mexico. Using findings from the bilingual indigenous language project, chapter 3 makes a strong case for a componential approach to the study of bilingual proficiency. Chapters 4 and 5 extend the discussion of the proposal for a componential approach beyond the local bilingual indigenous language context. Chapter 6 assesses research on some of the major topics in bilingualism research, such as the status of the biological endowment (i.e., Universal Grammar) and the role of critical period effects in L2 learning, and discusses how a serious study of child language attrition can help shed light on how universal properties of linguistic competence develop in the bilingual mind. Chapter 7, which focuses on academic language proficiency, assesses studies of bilingual and L2 literacy. It proposes that the two key components of academic language proficiency are secondary discourse ability and metalinguistic awareness and provides a framework for distinguishing between them. Chapters 8 and 9 resume discussion of the local context—namely, the Nahuatl-Spanish bilingual community in Mexico. Their focus is on metalinguistic awareness as an important aspect of literacy learning in children, particularly in learning to read (chapter 9) and write (chapter 8). The concluding chapter eschews holistic approaches to the study of bilingual proficiency and makes a compelling argument as to why a componential approach would be more productive. Following the chapters are four appendices containing data that illustrate the key concepts addressed.

What distinguishes this book from many other works on indigenous language and culture is its cognitive science perspective, which it successfully draws on and applies to the study of bilingual research problems. By linking the most theoretical aspects of bilingualism with the most practical ones, Francis succeeds in forging the way for future research to connect issues in child bilingualism with broader cognitive and linguistic issues.