To explore some of the ways in which notions of grammaticality reflected in secondary English language textbook series affect a student's acquisition of standard English and his attitude toward language, (1) statements which authors of widely-used textbooks made about standard English and why it is taught in the schools were compared with comments on the same subject by those knowledgeable in education and linguistics; and (2) grammatical information of the textbooks was analyzed according to conformity to the known structure of English, conformity to empirically established norms, consistency from one text to another, and intelligibility. Textbook analysis revealed that treatments of the subjunctive and of three aspects of the genitive misrepresent the standards and violate the structure of the language, conflict with one another, and are frequently unintelligible. The textbooks provide no principled basis for determining the grammaticality of an utterance. In matters of pronunciation, a lack of knowledge and misrepresentation of the facts of the language are demonstrated--e.g., statements ignore regional variation, thereby creating a false impression of inferiority with respect to any local standard. Evidence also suggests that current textbooks hinder the acquisition of standard English by nonstandard-dialect speakers. (MF)