A solid command of English grammar is a prerequisite for success when students take the SAT and/or ACT. This workbook presents a detailed grammar review with dozens of practice quizzes and exercises to sharpen students' skills. It begins with an explanation of grammatical terms and their functions. It then introduces the 24 most common grammar and usage questions that appear on the SAT and ACT and how to answer them. Prominent among them are questions on agreement between subject and verb, use of pronouns, verb forms, parallel structure, and diction. A final chapter focuses on advice and instruction for writing error-free SAT and ACT essays. This workbook is filled with sample questions exactly like those found on both the SAT and ACT, and comes with fully explained answers.