Here are some links to activities you could try for a bit of SPAG revision
Worksheetworks lets you design your own worksheet to help you practice the parts of grammar you are struggling with. It also gives you the answer sheet!
Lots of links to worksheets on all aspects of grammar, including punctuation.
Lots of worksheets to help you out with using contractions (words that use an apostrophe to 'contract' (join together) two words) Remember the apostrophe takes the place of the missing letter/s
Find an antonym to these words. Start on about Grade 8