It’s finals week here which means that I’ve been reading essay after essay, marking comma error after comma error. I would like to say that only the first year freshmen make these mistakes, but unfortunately, even my senior Creative Writing students struggle with commas.

In some fantasy writing dreamworld, we could throw commas around haphazardly, giving readers dramatic pauses, but sadly, that’s not the case. There are non-negotiable rules for comma usage in the English language. If you apply the rules correctly, your writing will have style, and happily for us, there actually aren’t that many comma rules, but who’s counting?

1. Use a comma following an introductory phrase.

Example: Standing at the podium, Patrick pontificated about his political beliefs. [participial phrase]

Example: With his notes forgotten at home, he gave an impromptu speech on the history of stand-up comedy. [prepositional phrase]

2. Use a comma following an introductory dependent clause. A dependent clause is a complete sentence that begins with a subordinating conjunction such as because, although, or if. You can find a list of them here.

Example: When Hillary’s alarm goes off in the morning, she always hits snooze at least twice.

3. Use a comma to break up elements in a series. When you use a comma after the last element and before the “and,” it’s called an Oxford comma. This comma is optional but either use consistently or don’t use it consistently, your choice.

Example with Oxford comma: My favorite genres to read are fantasy, historical, and mystery.

Example without Oxford comma: My favorite genres to write are young adult, historical and mysteries.

4. Use commas around “interrupters” or “parenthetical comments.” An interrupter is any part of the sentence that could be removed and the sentence would still “work.”

Example: Camden leaned back in his chair, his legs stretched out in front of him, trying desperately to come up with an idea for his story. [non-restrictive clause]

Example: The stack of novels on Brianne’s desk, teetering and wobbling, made Rachel start with fright when they began to topple. [adjectives]

Example: Jacob, the military guru, read another history of WWII. [appositive phrase]

5. Use commas before the coordinating conjunction (and, or, for, nor, yet, but, so) in a compound sentence. A compound sentence is two complete sentences joined by a coordinating conjunction, so you only need a comma if what follows the conjunction is a complete sentence.

Example: The first novel Shelby wrote was a fantasy, and she got tired of writing about dragons and elves.

Example: For her second novel, Shelby tried writing mysteries and had fun coming up with red-herrings and real clues. [There is no comma necessary in this example because “had fun coming up with red-herrings and real clues” is NOT a complete sentence.

6. Use commas in dates and places.

Example: Crystal plans on traveling to London, England on June 16, 2015.

The MOST COMMON comma error I see teen writers make is called a comma splice which is a specific type of run-on sentence. This happens when you separate two complete sentences with a comma instead of a period. Watch out for those in your writing.

Example: Although Amber’s giant purple laptop took up her entire desk, she didn’t care because she loved the big screen, she could have multiple documents open at once that she could see at the same time.

There should be either a period between “screen. She,” a semi-colon between “screen; she,” or a coordinating conjunction: “screen, and she.”

The above six rules are the “hard and fast” comma rules in English. But, you can also use commas for style, to give your reader a pause or to create voice. This is most often done when writing dialogue or setting a mood.

For example, to describe character who is running or terrified, you might have a series of short sentences separated by commas instead of periods.

If you want to write, learn these rules.  One of the best resources is Strunk and White’s Elements of Style. If there’s a classic text on grammar, punctuation, and writing, this is it. Get it.

What grammar or punctuation rule do you struggle with the most? Leave a comment and I’ll address it in a future post.