The last post on here challenged folks to correctly match the colors on several color strips. After scoring poorly on the test (I'm not a designer) and straining my eyes in the process, I needed a confidence boost.Enter grammar quizzes. Take that art directors and designers. See if you can adequately distinguish gerunds, avoid comma splices or even (gasp) S-P-E-L-L.
10 Grammar Questions This is a company's site that will help you if you fail.
Interactive Quizzes Lots of quick quizzes covering spelling, vocab and general stuff.