Learning French from Spanish and Spanish from French provides adult English speakers who have learned either Spanish or French as a second language with the tools to learn the other as a third language. Research in the growing fields of third-language acquisition and multilingualism documents how successful language learners intuitively build on their existing knowledge as they learn a new language. In this vein, Learning French from Spanish and Spanish from French takes advantage of the fact that learners with intermediate proficiency in a second language are used to thinking consciously about language, know themselves as language learners, and can capitalize on what they know about one language to understand the other. With chapters conveniently organized by grammatical concept and including supplementary resources such as exercises, parallel reading texts, and audio files, this book will benefit students, travelers, and budding multilinguals alike.