While demonstrating the practical realities of acceptable usage, Grammar Matters answers two questions: First, "What exactly is grammar?" Second, "Why is it necessary to use grammar correctly?" In down-to-earth, no-nonsense language, the authors emphasize how grammar varies with custom and how the rules of grammar were invented out of necessity. Put a different way, the authors suggest that writing considered grammatical is always appropriate in its language whereas language that is not appropriate to the occasion or the audience is likely to be judged ungrammatical . Grammar Matters begins with the basic sentence--as seen from the viewpoint of native speakers as well as students learning English as a second language. Then the book moves briskly into the twenty most common sentence errors and how to fix them. Every topic is followed by drills, practice, and MyWritingLab skill sets that promise complete understanding and overall mastery.