Language Files has become one of the most widely adopted, consulted, and authoritative introductory textbooks to linguistics ever written. The scope of the text makes it suitable for use in a wide range of courses, while its unique organization into student-friendly, self-contained sections allows for tremendous flexibility in course design. The thirteenth edition has been revised, clarified, and updated throughout to ensure that it remains the most comprehensive and accessible introductory linguistics textbook on the market. The revised chapter on morphology includes a more thorough discussion of allomorphy and adds sections on templatic morphology, suprasegmental morphology, and morphological metathesis to give students a more complete picture of all morphological phenomena. The chapter on language and computers has been updated with new sections on deep learning, artificial neural networks, and on other areas of computational linguistics, providing readers with a better sense of current research and applications in this rapidly developing field. Other additions include new sections on syntactic non-constituents and non-generative rule systems in the syntax chapter and a complete rewrite to the creole languages file in the language contact chapter. We have also adopted the use of the singular they when referring to a generic person whose gender is unknown or irrelevant. Exercises and lists of other readings have been updated throughout.