A cogent, freshly written synthesis of new and classic work concerning crosslinguistic influence, or "transfer," this book will become the authoritative account of transfer in second-language learning and its consequences for language and thought. Transfer in both production and comprehension is treated extensively, and new ideas such as the distinction between semantic and conceptual transfer, lateral transfer, and reverse transfer are given the attention they deserve. The book will be of considerable interest to students and scholars in the fields of second language acquisition, bilingualism, and applied linguistics.