 As French is a pluricentric language, Standard French encompasses various linguistic norms (consisting of prescribed usage).The syntax, morphology, and orthography of Standard French are explained in various works on grammar and style such as the "Bescherelle", a reference summary of verb conjugations first compiled in the 19th century by Louis-Nicolas Bescherelle from France, and "Le Bon Usage" written in the 20th century by Belgian grammarian Maurice Grevisse.In France, Standard French is based on the pronunciation and vocabulary used in the formal registers of French in Metropolitan France.