Top 20offers instruction and practice of twenty grammar points, all essential to good English writing. Because editing is an important skill in academic writing, a large number of the exercises deal with the development of this ability. In particular, the exercises attempt to draw students' attention to common grammatical errors and then teach them various ways to make corrections.Top 20can be used in writing classes with any text (such asGreat Paragraphs, Great Essays, Blueprints 1,andBlueprints 2) or as a stand-alone for a grammar class. Each of the 20 grammar points in the text is broken down into 4 or 5 subsets so students gain a deeper understanding of correct usage.