An overview of language concepts suggests applications of linguistics to the teaching of English at all levels of instruction. Traditional grammar, with its emphasis on syntax and written language, is discussed and then compared to generative grammar, with its emphasis on transformational theory. A discussion of usage summarizes the changes in varieties, levels, and styles of usage, and examines some of the more useful sources of usage information--dictonaries, linguistic atlases, usage manuals, and scholarly treatments of English grammar. The relation of linguistics to the teaching of composition, literature, reading, and spelling is analyzed, and the responsibility of the language curriculum for developing the critical readers and responsible writers essential to a democracy is emphasized. (LH)