What is grammar? The course offers reflections on Italian grammar. Starting from the etymology of the word and a study on Luca Serianni’s book, it deals with the main issues of contemporary grammar, its norms and usage, in the written and spoken language. A study of Paolo D'Achilles’s manual will enable students to sort out any doubts or gaps of a grammatical nature, to progress in their knowledge of Italian structures, both spoken and written, and to think about the language both in its synchronic and its historical-diachronic dimension. Through the analysis of the most common grammatical errors found in written texts, the course aims to sensitize students on the crisis points of our linguistic system; at the same time it aims to promote a thorough knowledge of Italian grammar and of the teaching tools for teaching this discipline.