Based on the broadest corpus ever analyzed (25 grammars published between 1440 and 1586), this study offers a comprehensive view of grammatical thought during the Italian Renaissance – the first of its kind since the works of Trabalza (1908) and Kukenheim (1932). Devoting a particular attention to the historical context, the method and structure of each work, it highlights three linguistic innovations: article, compound tenses, and conditional.