The label `semiotic grammar' captures a fundamental property of the grammars of human languages: not only is language a semiotic system in the familiar Saussurean sense, but its organizing system, its grammar, is also a semiotic system. This proposition, explicated in detail by WilliamMcGregor in this book, constitutes a new theory of grammar. Semiotic Grammar is `functional' rather than `formal' in its intellectual origins, approaches, and methods. It demonstrates, however, that neither a purely functional nor a purely formal account of language is adequate, given the centrality of the sign as the fundamental unit of grammaticalanalysis. The author distinguishes four types of grammatical signs: experiential, logical, interpersonal, and textural. The signifiers of these signs are syntagmatic relationships of the following types, respectively: constituency, dependency, conjugational (scopal) and linking (indexical,connective). McGregor illustrates and exemplifies the theory with data from a variety of languages including English, Acehnese, Polish, Finnish, Japanese, Chinese, and Mohawk; and from his pioneering research on Gooniyandi and Nyulnyul, two languages of the Kimberleys region of Western Australia.