McGregor proposes and develops a new theory of grammar based on the notion of the linguistic sign. In interpreting language and its structure as a semiotic system consisting of signs, he provides a range of new analyses of well established syntactic and morphological relations, categories, and roles. This book constitutes an important and valuable contribution to linguistic theory, drawing on the author's extensive knowledge of Australian Aboriginal languages, as well as discussing data from more familiar languages, such as English.