This doctoral dissertation constitutes an excellent example of how linguistic theory can contribute to the formulation of testable hypotheses about the nature of language acquisition. Taking as a point of departure Chomsky's Principles and Parameters model and the Minimalist Program, the author carries out a careful and detailed analysis of the status and development of the Determiner Phrase (DP) in two different sets of data: (a) bilingual (French-Swedish) first language (L1) developmental data produced by three children, and (b) second language (L2) French developmental data produced by eight Swedish adult speakers.

The first three chapters present, respectively, the main objectives of the study, the theoretical framework—both from a learnability and from a syntactic perspective, and a description of the corpora and the methodological decisions guiding the data analysis.

Chapters 4–6 constitute the main body of the dissertation. Chapter 4 provides an analysis of null determiners, null subjects, and root infinitives to show that the development of null determiners does not parallel the development of null subjects and root infinitives in this bilingual grammar. As for the adult L2 grammar, the omission of determiners is very limited and occurs in typologically marked contexts or in contexts where null determiners are possible in the L1 (Swedish) grammar. Chapter 5 addresses the status of definite articles in these two grammars; it shows that, although the definite article occupies the determiner head in the bilingual grammar from a very early stage, it occupies the specifier head of the DP in the early L2 adult grammar. In chapter 6, it is argued that the status of the definite article as head, together with the relationship between its phonological and syntactic properties, triggers the acquisition of the gender feature in the bilingual grammar but not in the L2 grammar. Number and gender features are said to develop in different ways between the two grammars and within each of them.

This book has the natural pros and cons of a doctoral dissertation. However, the careful, precise, and creative way in which the syntactic analyses and the empirical data are linked, as well as the interesting proposals concerning the differences between the two grammars, make this a very stimulating volume for both linguists and psycholinguists.