The Oxford Comma: When and How To Use It (And Why It Causes Fights)

The Oxford comma (also called the serial comma) might be the most controversial punctuation mark ever. People fight over it. Heated words are exchanged. Angry glares are inevitable. Broken friendships are possible.

Seriously, though, there has been many an argument between an author and their publisher when it comes to this tricky little punctuation mark. In fact, the Oxford comma (or, rather, the lack of an Oxford comma) once cost a dairy company in Maine $10 million when a lawsuit concerning overtime pay was set against them based on a state law with some ambiguous wording. (You can read all about that scandal here!)

Although folks have generally come to a consensus about some rules for the Oxford comma, there are still many instances when its use is simply a matter of where you live and who you’re writing for.

What Is It?

So what IS this controversial serial/Oxford comma? It’s simply the comma that comes before the last item in a list (and before the preceding “and”).

I ate a sandwich, watermelon, and a popsicle at the picnic.

Those who DON’T like the Oxford comma would write this sentence like this:

I ate a sandwich, watermelon and a popsicle at the picnic.

Here are a couple more examples of lists with the Oxford comma:

This morning, I went for a jog, walked my dog around the block, and took a shower.

To get to Lindsay’s house, drive about three miles until you see McDonald’s on the right, turn left and keep driving until you get to the stoplight, and park at the fourth house on the left.

According to Merriam-Webster, it’s been called the serial comma since 1922 and was given the name Oxford comma in 1978.

Though the serial comma has been around for hundreds of years, it was nicknamed the Oxford comma after Peter Sutcliff called it that in his book about the history of Oxford University Press. Horace Hart (the printer for Oxford University Press from 1839 to 1915) wrote about this comma in 1905 in his style guide, Hart’s Rules for Compositors and Readers, which set up the Oxford comma as a standard for employees working at the press at that time.

Why Should You Use It?

I’m a big fan of the Oxford comma, mainly because it promotes clarity in almost every situation where it’s used. Omitting the Oxford comma could cause serious confusion, as in this case:

I’d like to thank my parents, the president and Taylor Swift.

In that situation, you’re unintentionally stating that your parents are the president and Taylor Swift. That is likely not the case, so the Oxford comma is necessary to clarify who you’re thanking.

I’d like to thank my parents, the president, and Taylor Swift.

The Oxford comma is also useful when the last item in a list is a pair.

For dinner, we had lasagna, salad, and bread and butter.

Without the comma there, it would look like you had butter as a side for dinner.

For dinner, we had lasagna, salad and bread and butter.

Another example of when the Oxford comma clarifies a list:

Cassie set the table, Lily served the fish, and John brought the dessert and games.

Without the Oxford comma, you might not notice where the second item in the list ends and the third begins.

Cassie set the table, Lily served the fish and John brought the dessert and games.

When you’re only partway through the sentence, it could be interpreted as “Lily served the fish and John,” meaning she served both the fish and John. The temporary confusion could be avoided by adding in that simple little comma.

Should You ALWAYS Use It?

If the Oxford comma is so incredibly for clarification, shouldn’t we just ALWAYS use it? Well…maybe not.

Some people think it’s redundant because commas in a list are supposed to serve as replacements for the words “and” or “or.” Instead of saying “I went to the store and the mall and the post office and my mom’s house,” we can replace a bunch of those “and”s with commas. Since “and” is already used at the end of the list (we wouldn’t say “I went to the store, the mall, the post office, my mom’s house), it might be seen as unnecessary to also include a comma.

When in doubt, however, I would recommend using the Oxford comma almost all the time, because it’s better to be MORE clear than accidentally unclear.

The only time when you should abstain from using the Oxford comma is when it actually inhibits clarity and could lead to confusion.

I visited my mother, the mayor, and my friend.

In that sentence, “the mayor” could be the second item in the list or it could be a clarification about who your mother is. Is your mother the mayor? If not, you should omit the Oxford comma to remove that confusion. But here’s a new problem: now you’re left with

I visited my mother, the mayor and my friend.

In that sentence, you could be listing three different people or saying that your mother is both the mayor and your friend. If that’s not the case, the best thing to do for clarity is just remove all the commas entirely.

I visited my mother and the mayor and my friend.

Why Can’t We All Just Get Along?

The divisive nature of the Oxford comma is historic and international. This controversial punctuation mark is more common in America than in Britain, but if you’re a journalist (even in America), you can pretty much forget it exists. OK, so journalists still use it sometimes, but generally news writing omits the Oxford comma. The Associated Press Style Guide (which is the most common guide for journalists) recommends against the use of an Oxford comma except where it would cause a problem or confusion to leave it out. This standard was established so that newspapers could save space and ink, but it’s stuck around even now that most news writing happens digitally.

The New York Times says that “news writing has traditionally omitted the serial comma—perhaps seeking a more rapid feeling in the prose, or perhaps to save time and effort in the old days of manual typesetting.” They clarified: “We do use the additional comma in cases where a sentence would be awkward or confusing without it: ‘Choices for breakfast included oatmeal, muffins, and bacon and eggs.'”

Most other style guides for American writing recommend using the Oxford comma, including the MLA, APA, and Chicago style guides. According to the Chicago style guide, “Chicago strongly recommends this widely practiced usage, blessed by Fowler and other authorities, since it prevents ambiguity.” So if you’re writing a research paper or any paper for school, you would be safer to use the Oxford comma more often than not.

When In Doubt…

If you ever have a question about whether you should use the Oxford comma, try to decide whether your sentence would be made MORE confusing by including it. If not, I’d go ahead and put it in, because more clarity is always better than less.

Commas Before and After a Series

The Oxford comma might not be the only one involved in your list! Should you include a comma BEFORE your list? ONLY do that if the rest of the sentence requires it, meaning there’s an introductory clause before the list begins.

Although he wasn’t hungry, pizza, garlic bread, and wings sounded delicious.

If you’re going to the water park, a swimsuit, goggles, and a towel are all required.

Otherwise, there’s no need to begin a list with a comma since those commas are serving as replacements for the words “and” or “or,” and you wouldn’t start a list with “and”:

I’m going to pick up, bacon, eggs, and milk at the store.

My favorite colors include, red, green, and blue.

Do you need a comma after the series? Again, you should only include that if the rest of the sentence requires it.

Books, pencils, and a lunch box, were all on the back-to-school shopping list.

Books, pencils, and a lunch box, but not pens, were all on the back-to-school shopping list.

Do you like the Oxford comma, or do you prefer to leave it out? Comment your preference! And don’t forget to sign up for my email newsletter so you never miss a post!

Want more punctuation information? Check out my post about the different kinds of dashes and when you should use each one!

Sources:

• American Psychological Association. Publication Manual of the American Psychological Association. 7th ed. Washington, DC: American Psychological Association, 2020.
• “America’s Most Trusted Dictionary.” Merriam-Webster. Accessed August 7, 2024. https://www.merriam-webster.com/.
• Corbett, Philip B. “FAQs on Style.” The New York Times, June 23, 2015. https://archive.nytimes.com/afterdeadline.blogs.nytimes.com/2015/06/23/faqs-on-style-2/.
• Einsohn, Amy. The copyeditor’s handbook. 3rd ed. Berkeley and Los Angeles, California: Univ of California Pr, 2011.
• MLA Handbook. 8th ed. New York: The Modern Language Association of America, 2016.
• Scribendi Inc. “Where Did the Oxford Comma Come from, and Why Is It so Important?” Scribendi. Accessed August 7, 2024. https://www.scribendi.com/academy/articles/oxford_comma_importance.en.html.
• The Chicago Manual of Style. 17th ed. Chicago, IL: The University of Chicago Press, 2017.
• Truss, Lynne. Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation. New York, NY: Gotham Books, 2003.