Daily Grammar provides simple and clear lessons on the basics of English grammar for grades 5-12. Set up in modules of five examples and a follow-up quiz, the simiplicity of the approach and the explanations make this a great site for students to use on their own when they feel they need self-paced remediation or enrichment. Mr. Bill Johanson, the author of the material, is a former junior and high school English teacher, with 30 years experience in the classroom.
Grammar Ninja is a fun game for students to play as they develop a working knowledge of the parts of speech. Grammar Ninja has three levels for students to work through. As long as you answer questions correctly, they continue through the game, but answer incorrectly and the words explode.
this site, maintained by RobinL. Simmons, provides grammar explanations and numerous interactive exercises handouts for teachers and students in grades 6-12.
The British Council's Learn English website offers 69 interactive activities for learning the rules of grammar. The activities are not listed by grade level so you will have to preview them to determine which activities are best suited for your students.
SoftSchools.com provides free math worksheets, free math games, grammar quizzes and free phonics worksheets and games. Worksheets and games are organized by grades and topics. These printable math and phonics worksheets are auto generated.
Free worksheets on a variety of topic for language arts (reading and writing, grammar, spelling phonics, handwriting) as well as math, science and social studies. There are also brain teasers and teacher helper tools such as award certificates, teaching tips, etc. In addition, there are holiday worksheets. This site would be great for differentiated activities. In a quick preview I saw they had worksheets that were of the same topic areas but they has easy and harder options available. This would be another good site to share with parents.