The value of grammar instruction in improving students' writing has been debated for at least 150 years, and is showing no signs of tiring. But would teaching grammar actually improve writing? In fact, study after study has shown that the study of grammar does not translate to improved student writing. Indeed, the basic skills of writing are not grammatical at all. Writing is not a bottom-up process moving from words, to sentences, to paragraphs, to the dreaded five-paragraph essay. Writing is a top-down process, and its "basic skills" are not grammatical rules, but rhetorical strategies pertaining to the different stages of the writing process: strategies for invention, research, arrangement, drafting, discussing, and revising. Those arguing that grammar instruction will improve students' writing need to recognize that, at most, the rules of grammar comprise one small piece of a complex process that begins with and supports the students' intention to communicate. (Contains 14 endnotes.)