Students can improve their writing skills by studying grammar. In learning to apply a logical system in their analysis of sentence parts, for example, students develop mental discipline. This discipline can be strengthened through the grammatical analysis of their own papers. In these evaluations, which include error and stylistic analyses and a prescription for improvement, students learn to identify and correct technical errors, reduce wordiness, and sharpen and reshape sentence structures. Because traditional grammar fails to provide a working model of the English language, however, evaluations based on it tend to be error-oriented, focusing on surface features such as sentence variety rather than on the relationship between these forms and underlying meaning. Classes having worked with transformational and structural grammar, on the other hand, produce grammatical self-analysis papers that do not simply pinpoint problems, but explore their relationship to content. In studying the new grammar's surface and deep structures, students have discovered that form affects substance. (MM)