This book is a thorough introduction to psycholinguistics, and shows how the area relates to psychology, linguistics, philosophy and education. It focuses on how young children acquire language and demonstrates how sign language helps us to gain a deeper understanding of the acquisition process. It also explores more complex and challenging topics such as mental grammar and sentence processing and the relationship of language to thought, the brain, society and culture. Other topics include second language acquisition processes, teaching methods and the cognitive impact of bilingualism.