Parsing and Grammar Description, Corpus-Based

English teachers and textbook authors often rely on their intuitions to choose the most important words and grammatical structures to focus on. For example, many English-language professionals believe that progressive aspect verbs (or 'the present continuous,' e.g., is working) are much more common in conversation than simple aspect verbs (e.g., works). As a result, the teaching of progressive aspect has often been emphasized at the expense of simple aspect. However, empirical corpus studies show that such intuitions about language use are often incorrect. This article introduces corpus analyses of grammar, illustrating the surprising research findings that result from this approach.