The first textbook to bring together the linguistics of both BSL and ASL, this accessible book provides a uniquely international and comparative introduction to the structure and use of signed languages. Presupposing no prior knowledge, it covers all levels of linguistic structure: phonetics/phonology, morphology, the lexicon, syntax, semantics and discourse. Photographic illustrations of BSL and ASL signs feature throughout every chapter, and are linked to over 150 online videos, making this a clear and immersive resource for anyone interested in sign language linguistics. End of chapter exercises, questions for discussion and annotated further reading suggestions allow students to fully engage with the material they have read, and to extend their learning independently.