Using frequency findings from corpus linguistics, this paper explores the relationship between the information presented in ESL-EFL materials and what is known about actual language use based on empirical studies. Three aspects of materials development for grammar instruction are discussed: the grammatical features to be included, the order of grammatical topics, and the vocabulary used to illustrate these topics. For each aspect, we show that there are often sharp contrasts between the information found in grammar materials and what learners encounter in the real world of language use. In our conclusion, we argue that a selective revision of pedagogy to reflect actual use, as shown by frequency studies, could result in radical changes that facilitate the learning process for students.