Hundreds of my SAT students at Tom Clements Tutoring in the San Francisco Bay Area can attest that mastering this short and simple list of 9 -- that's it, just 9 -- user-friendly grammar rules is a surefire way to ace the SAT Writing section. These same rules are now incorporated in a cool, interactive app that provides three levels of expertise:

1) Study -- this concept level describes the 9 rules you need to obtain top scores on the grammar section. Graphics and a slideshow movie make the rules easy to learn and fun. Interactive practice questions for each rule reinforce the concepts.

2) Jumbles -- this strategic level mixes interactive questions from the first level in random order, forcing you to think on your feet.

3) Test -- this advanced level provides SAT-style questions specifically designed to reinforce the rules presented in the app.