Every grammar of French is faced with the problem of how best to explain the correct usage of the grammatical part-system accord du participe passé in all its complexities and inconsistencies. The present volume pursues two objectives, the one being to give the reader a systematic overview of the rules involved and the specific problems they present, the other to essay a selective analysis of French grammar description from the Renaissance to the present, with reference to the handling of this particular accord phenomenon. It transpires that this instance of accord is a genuine test case, a concrete feature of grammatical analysis revealing the strengths and weaknesses of the various conceptions underlying the grammars in question.