New in paperback. Hardcover was published in 2018. This Handbook offers a developmentally oriented and socially contextualized survey of research into individual bilingualism, comprising the learning, use and, as the case may be, unlearning of two or more spoken and signed languages and language varieties. A wide range of topics is covered, from ideologies, policy, the law, and economics, to exposure and input, language education, measurement of bilingual abilities, attrition and forgetting, and giftedness in bilinguals.