Corpus-based instruction, also referred to as corpus-based linguistics, is essentially the study of genre texts for the production of materials that fit a specific group of second language learners. For example, if a group of students is learning the language in order to read medical articles, a specific teaching program can be set up based on the text analysis of the genre and corpus linguistic tools. The strength of this procedure is that word associations represent meanings, or functions. Because language teaching is essentially relating language forms to language functions, corpus-based instruction provides a rich learning environment. The opportunities provided by improved technologies make it possible for a few large collections of texts, or corpus texts, to be computer processed. Computer tools for text analysis reveal significant patterns that can be used instantly by learners. Such significant patterns are generally hidden when the texts are analyzed manually. Furthermore, because the texts forming the corpus represent a specific genre of writing, language forms and language functions relate grammar to discourse. This additionally draws attention to the presence of specific grammar for specific types of discourse. (Contains 20 references.) (Author/KFT)