The grammar of a language is not only un système ou tout se tient; it also lies within a nexus involving time, space, and social relationships. On the dimension of time, descriptive and historical linguistics are not totally separate: native speakers’ knowledge of their language may include recognition of archaic forms and foreign borrowings. As for space, native speakers’ knowledge also includes awareness of geographical dialect variation. On the social dimension, the relevance of sociolinguistic variation is now widely recognized. Linguists who undertake to write grammars should consider all these factors, particularly as regards the interrelatedness between the grammar, the lexicon, and text collections.