Current research on multilingual acquisition is concerned with whether children exposed to multiple languages from birth build separate language systems from early on or a single system comprised of elements of all languages. While several studies have shown that developing bilinguals show signs of language differentiation from the onset of speech, very little work has been done on children learning more than two languages. This book examines the emergence of three languages - Tagalog, Spanish, and English - in a child raised in a trilingual environment and focuses on the process of language differentiation from the perspective of phonology, lexicon, word order, and language choice. These analyses shed light on a child’s ability to develop the various components of three languages and suggest that multilingual exposure does not slow down the process of language differentiation. ??The results of this study and their implications will be of interest to those working in linguistics, developmental psychology, and related fields, interested in the processes and mechanisms involved in multilingual children’s language and cognitive development.