Columbia Common English Usage Mistakes at ACT is compiled to help you learn the absolutely essential grammar testing points and avoid the most common mistakes at ACT to raise your score! It has twenty lessons with each one having the following outstanding features: 1. ERROR EXAMPLES: show you what kinds of mistakes most often made at ACT and how to correct them; 2. GRAMMAR GUIDES: teach you the grammar rules absolutely essential to raise your ACT score; 3. PRACTICE TESTS: Use sample Sentence Correction and Sentence Completion questions to test your grammar power and readiness for the real ACT; 4. ANSWER KEYS: provide answers and explanations to help you avoid the mistakes forever to score higher on the ACT! Columbia Common English Usage Mistakes at ACT is your grammar Bible! With the help of our fun and effective way to learn all the essential grammar testing points, you will be able to score higher on the ACT guaranteed!