This book examines the rhetorical function of French verb forms in scientific writing. It includes both statistical descriptions of the frequency of verb forms and also examines their semantic function as this applies to communicating about science and technology in French. The book takes as its core argument the idea that grammatical choices are meaningful for the creation of text and are deployed to construct particular understandings of the information communicated. The language used in communicating science is distinctive and patterns of language use in scientific writing are different from those of other sorts of texts. In order to examine the functionality of grammar and its relations to communicative purposes, this book takes as its starting point the idea that grammar is not unitary, that is grammatical structures are not invariable in their meaning. While the forms of language structure may be identical in general and specialized varieties of a language, the meanings of these constructions are not. The book’s semantically-based view of grammar allows grammar to be seen not as a linguistic given determined by structural conventions, but rather as a symbolic activity which is determined by and is determining of communicative practices.