To perform well on the ACT English test, students need to have a thorough understanding of basic grammatical concepts and sentence structure. ACT English Mastery Level 1, contains 25 lessons, 375 practice questions, and 10 mini-tests derived from some of the most commonly missed items on the ACT English test. Also included is a unique English glossary, which expands upon the words and phrases used in this workbook, to aid in learning and help prevent confusion.