Book excerpt: This student-friendly grammar guide helps students recognize, correct, and avoid the most common and serious grammar and usage errors. The text breaks complex concepts down into simple lessons, each focusing on a single essential skill. Everyday language and easy-to-remember tips make grammar easy to understand, and clear examples and diagrams show, rather than just tell, how to identify and correct problems. Hundreds of exercises in the book and thousands more at Exercise Central provide students with plentiful practice.