This textbook deals with the grammatical category of person, which covers the first person, the second person, and the third person. Drawing on data from over 500 languages, Anna Siewierska compares the use of person within and across different languages, and examines the factors underlying this variation. She shows how person forms vary in substance, in the nature of the semantic distinctions they convey, in how they are used in sentences and discourse, and in the way they function to convey social distinctions. By looking at different types of person forms in the grammatical and social contexts in which they are used, this book documents an underlying unity between them, arguing against the treatment of person markers based on arbitrary sets of morphological and syntactic properties. Clearly organized and accessibly written, it will be welcomed by students and scholars of linguistics, particularly those interested in grammatical categories and their use.