When Quirk gathered his Survey of English Usage in 1959, his objective was to make grammars in order to face the increasing want of English Teaching as a foreign language in post-war years. Grammars should be both descriptive and prescriptive. His method was to discover new descriptive patterns by a systematic study of usage in order to establish new prescriptions, thus objectively based. Quirk’s conception of usage raises several questions: - How Quirk’s views are anchored in the British tradition of descriptive grammars and dictionaries based on usage, and of empirical linguistics? - Which conception of language is conveyed by his conception of usage ? How usage can be combined with the notions of performance and acceptability he borrowed from the then emerging Generative Grammar ? - How the notion of Standard English can be combined with usage, variation and norm, when gradience of variations becomes a key feature of usage, and when micro-grammars adapted to different restricted languages are advocated against a single prescriptive grammar?