In order to become a better writer and speaker, you must first master grammar rules. Proper use of grammar gives credibility to your writing as well as gives you an authoritative speaking voice. If you want to improve your grammar, there are several resources you can turn to for help.
Use Grammar Books
Go to your local bookstore and go to the "Reference" section.
Look for English grammar books.
Find books that have quizzes and/or exercises in them.
After each lesson, take each practice test/quiz and look over your answers. The more you practice, the better you will be at writing.
Take an English Class
Research your local community colleges and see which colleges offer English remedial classes. These classes usually review grammar points.
Choose a class that fits with your schedule.
Enroll in the class.
Ask your instructor questions if you are having difficulty understanding certain concepts.
Use Online English Grammar Tutorials
Google phrases such as "English grammar tutorials" or "English grammar."
Click on links referring to English grammar tutorials.
In addition to grammar lessons, make sure that sites have interactive activities where you can test yourself on your grammar. Helpful websites can be found in the "Resources" section.