I’m not sure if there is any other punctuation that evokes so much derision and debate as the serial (or Oxford) comma. It goes by “serial” and “Oxford,” for the Oxford University Press style guide, which advocates for the serial comma (even though it’s generally more common in American English usage than British English).
For those unfamiliar, the serial comma is an optional comma before the word “and” and at the end of a list of three or more. This creates a slight pause before the last item in the list, making it clear that each part of the list (in this case 'my dogs,' 'Steven,' and 'Mary') is a separate item.
Here are a few examples:
"I need to pick up my dogs, Steven and Mary."
"I need to pick up my dogs, Steven, and Mary."
Are your dogs named Steven and Mary? Or do you need to pick up your dogs and Stephen and Mary?
“Angie went into the lake with her sister, a doctor and a ballerina.”
“Angie went into the lake with her sister, a doctor, and a ballerina.”
So are there three people going to the lake with Angie? Or is Angie’s sister a doctor and dancer?
Proponents say the serial comma provides clarity, while critics say it provides redundancy. But those in favor are losing the battle, as The Associated Press and New York Times style guides have already done away with it.
Perhaps most important (at least to me, as an editor) is that regardless of how you feel about the serial comma, inconsistency looks improper and is the worst thing for your writing. So, it’s smart to develop a standard for how you’ll use the Oxford comma in your own writing. Learning to use the Oxford comma correctly can have a significant impact on the clarity of your writing.
After all, the Oxford comma has the potential to change the meaning of a sentence completely. A favorite of the pro-comma group:
“Eat, Grandma!” vs. “Eat Grandma!” (Telling Grandma to eat takes quite a turn, without the Oxford comma.)
All joking aside, while the Oxford comma is usually necessary, it can also be confusing. To that end, here are three tips to remember:
1. Always use the comma in long, complex lists.
Example: “Alison went to the store and got caviar, cheese, crackers, soy sauce, Sprite, cookies, bread, and toenail clippers.” The Oxford comma in this sentence appears right before the last “and” and helps to simplify the phrase.
While it’s fine to omit the Oxford comma in a short list (“Alison went to the store and got cheese and crackers”) it helps to streamline longer lists and is essential in any lists that includes a variety of products, goods, or services, for example.
2. Use the serial comma in any sentence that needs additional clarification or could be confusing without it.
Because the Oxford comma helps to break up topics and keep the message clear for readers, it’s an essential way to keep mix-ups to a minimum and help your readers digest the essential meanings of your content.
Here’s an example: “I had toast, eggs and cheese.”
Without the Oxford comma, it sounds like you’re telling your friends, Eggs and Cheese, that you had toast for breakfast.
3. Use the Oxford comma before the final item in any list of three or more.
This helps avoid confusion and streamline your writing. It also helps keep your material consistent, and saves you from looking like an amateur to your audiences.
The only exception to rule #3 is when the last item in a series contains a conjunction.
Example: “I had eggs, cheese, coffee and cream for breakfast.” If you put a comma before “and cream,” it would indicate that you had cream all on its own, rather than in your coffee which (hopefully) isn’t true!
While a contentious piece of punctuation, knowing how to use the Oxford comma can help simplify its place and purpose in your writing. This simple little piece of punctuation is critical for helping avoid confusion and streamline your writing.