Although usage-based approaches have been successfully applied to the study of both first and second language acquisition, to monolingual and bilingual development, and to naturalistic and instructed settings, it is not common to consider these different kinds of acquisition in tandem. The present volume takes an integrative approach and shows that usage-based theories provide a much needed unified framework for the study of first, second and foreign language acquisition, in monolingual and bilingual contexts. The contributions target the acquisition of a wide range of linguistic phenomena and critically assess the applicability and explanatory power of the usage-based paradigm. The book also systematically examines a range of cognitive and linguistic factors involved in the process of language development and relates relevant findings to language teaching. Finally, this volume contributes to the assessment and refinement of empirical methods currently employed in usage-based acquisition research. This book is of interest to scholars of language acquisition, language pedagogy, developmental psychology, as well as Cognitive Linguistics and Construction Grammar.