1. Commas used to set off quoted elements. Ex. The great philosopher Forest Gump once said, “Life is like a box of chocolates,” and these great words made him a household name.
2. Commas used to set off phrases that express contrast. Ex. Although he was no Einstein, Forest Gump spoke great truths about human nature and the beauty of living.
3. Commas used to set off free modifiers. Free modifiers are phrases or clauses that usually come at the end of a sentence and can be removed or moved somewhere else in the sentence without compromising the meaning of the sentence. These phrases or clauses are not complete thoughts or sentences on their own. Ex. People eagerly absorbed the philosophy of Forest Gump, desperately hanging onto his every word.
4. Commas used to set off all geographical names, items in a dates (except month and day), addresses (except the street number and name), and titles in names. Ex. For instance, Forest Gump once spoke about a shrimp-loving man from Bayou La Batre, Alabama.
5. Commas used to generally avoid confusion. Ex. From the parable of the shrimp-loving man, Bubba, people learned that there are many fine ways to spice up and enjoy shrimp and, like shrimp, there are just as many ways to spice up and enjoy life.

Believe it or not, rules of comma usage are not as confusing as they seem. In fact, correct and effective comma usage centers upon the simple question of clarity. While not using enough commas can lead to an unclear and confusing sentence, using too many commas can result in an even greater sentence disaster. I think I echo the sentiments of most current and former writing teachers and lawyers when I say that a sentence with too many commas is like driving over a street with too many potholes: just like those potholes will eventually wreak havoc on your car, too many commas will wreak havoc on your writing. Besides causing general confusion, a sentence with too many commas presents a special kind of annoyance for the average reader. As a result, it’s very important 1) to commit the rules of comma usage to memory and 2) to focus on the ensuring clarity.

Commas, like most elements of grammar, serve one overarching purpose: to provide clarity. Whenever you become confused or uncertain about whether to use a comma, stop, take a deep breath, hug your dog or cat, and ask yourself a couple of questions. Would this comma make the sentence or thought clearer? Would that comma confuse the reader and make the sentence less clear? Now, when or if you get stuck on such questions, revisit some of the rules I’ve laid out in these posts (here and here) to help you find the answer. Remember: as much as you need commas, too many can lead to unpleasantness. Nobody likes driving over a bunch of potholes. If you go through all of these questions and revisit the rules but still remain uncertain about whether you need a comma in a particular instance, then chances are you don’t need a comma in that instance. With any sentence, clarity is your main goal. Commas should further that goal rather than get in the way of it.

Don’t get annoyed. Don’t feel like an idiot. Commas trip up writers with varying degrees of experience and skill. I still sometimes have comma struggles. Review the previous posts on comma usage and then try some fun online quizzes to test and refine your comma knowledge. Eventually, you’ll get to a point where you hardly think about commas. At that point, you will become one of the geniuses of our time, joining the ranks of Forest Gump and Albert Einstein. So press on, write for clarity and conquer those tricky commas.