If you've ever paused mid-stroke and thought "Does this need an apostrophe?" you'll want to take a peek at the apostrophe-use flowchart at Apostrophe.me for a cartoon-driven refresher.
The flowchart asks simple questions like "Is it plural?" and "Are you indicating possession?" to drive the flow through all the potential situations in which you would use an apostrophe. The flowchart ends with a gigantic piece of parting advice: When in doubt don't use an apostrophe. Apparently a lot of us get ourselves into a bit of trouble throwing around extra apostrophes with a little too much abandon. Even if you're a master of the apostrophe (and we suspect many of our attention-to-detail readers are), it could be worth sending on to someone you know needs a little help from time to time.
Check out the flowchart for a full rundown on apostrophe use — and to take a gander at the kittens riding a goat and the singing dinosaur. Have a favourite site to get your grammar questions answered? Let's hear about it in the comments.