Studies of bilingual behavior have been proliferating for decades, yet short shrift has been given to its major manifestation, the incorporation of words from one language into the discourse of another. This volume redresses that imbalance by going straight to the source: bilingual speakers in their social context. Building on more than three decades of original research based on vast quantities of spontaneous performance data and a highly ramified analytical apparatus, Shana Poplack characterizes the phenomenon of lexical borrowing in the speech community and in the grammar, both synchronically and diachronically. In contrast to most other treatments, which deal with the product of borrowing (if they consider it at all), this book examines the process: how speakers go about incorporating foreign items into their bilingual discourse; how they adapt them to recipient-language grammatical structure; how these forms diffuse across speakers and communities; how long they persist in real time; and whether they change over the duration. Attacking some of the most contentious issue in language mixing research empirically, it tests hypotheses about established loanwords, nonce borrowings and code-switches on a wealth of unique datasets on typologically similar and distinct language pairs. A major focus is the detailed analysis of integration: the principal mechanism underlying the borrowing process . Though the shape the borrowed form assumes may be colored by community convention, Poplack shows that the act of transforming donor-language elements into native material is universal. Emphasis on actual speaker behavior coupled with strong standards of proof, including data-driven reports of rates of occurrence, conditioning of variant choice and measures of statistical significance, make Borrowing an indispensable reference on language contact and bilingual behavior. "It is an exceptional academic pleasure to review a book that you can recommend in the highest possible terms: Shana Poplack's new monograph is innovative, thorough, extremely well documneted, with a potential to become both a game-changer and immediate classic." -- Olga Timofeeva, English World-Wide "The field of bilingualism has been waiting more than fifty years for a thorough study of the process of borrowing in bilingual speech. Shana Poplack's wonderful book is finally here to help us understand the process by which bilingual speakers adapt words of one language into the other in their interactions. Her brilliant research is sure to take its place right next to the seminal work of Einar Haugen and Uriel Weinreich in the years to come." --François Grosjean, Professor Emeritus, Neuchâtel University, Switzerland A masterful achievement, built on detailed qualitative analysis, advanced sampling methods, and innovative statistical techniques. Comparing bilingual and monolingual stretches in the same speakers rather than relying on standardized descriptions, Poplack establishes the relatively low frequency of language mixing; the predominance of single-word items that are distributionally and morphosyntactically adapted to the recipient language from the very first instance of use; and their treatment by the community as nonce borrowings rather than single-word switches. Loanwords documented in dictionaries did not start out as switches, but become swiftly established, maintaining however a high degree of phonetic variability, similar to that of new nonce loans. Clear and to the point -- a major contribution by one of the masters of the field."--Ricardo Otheguy, Professor Emeritus of Linguistics and Director of Research Institute for the Study of Language in Urban Society (RISLUS) Shana Poplack is Distinguished University Professor and Canada Research Chair in Linguistics and director of the Sociolinguistics Laboratory at the University of Ottawa. Her work applies theoretical and methodological insights gained from the study of linguistic variation and change to a variety of fields, including bilingual language mixing, language contact and grammatical convergence, the genesis of African American Vernacular English, normative prescription and praxis, and the role of the school in impeding linguistic change.