Practice at online websites like Learn English, English Grammar, English Daily, and Guide to Grammar and Writing. All of the websites offer free practice quizzes to help you learn all aspects of English grammar. Follow the instructions at each site.
Call your local high school or college. Some schools may allow you to sit in on classes, or someone might know of an educator willing to help you at no charge.
Borrow books from the library. Don't be shy about checking out books aimed at young children. These books simplify grammatical rules.
Websites like To Learn English, Super Teacher Worksheets, and Using English offer free worksheets you can download and work on at your own pace.
Play free online games at Marks English School, Games Zone, and Road to Grammar. These sites have games like basketball, the Grammar of Doom, and Frog Verbs. Answer the questions to win the games.