These sites will help you practice your English grammar skills in many different ways.
1. Classroom Games for Intermediate & Advanced English Learning, Teaching. http://www.eslgamesplus.com/intermediate-classroom-games/ Good site for grammar games
2. English Grammar Lessons. http://www.englishgrammarsecrets.com/index.html This site explains and teaches the many parts of speech, verb tenses etc.
3. ESL Interactive Grammar Games, EFL Interactive Grammar Quizzes. http://www.eslgamesworld.com/GrammarGames.html This site has many ways to practice grammar
4. http://a4esl.org/ This site has grammar quizzes and other learning activities. It has bilingual activities available in many different languages.