Comma Use Rules and Guidelines

Comma use is a hot-button issue among grammar enthusiasts. Commas are frequently misused, though some argue that the rules for how and when to use commas are somewhat lax. Either way, we will cover when to use a comma, when NOT to use a comma, and why there are some exceptions to the rules.

What are the eight rules for commas?

You may have heard that there are only eight rules for commas—and that’s true. The rules governing comma usage are actually pretty simple and straightforward! Let’s take a closer look at each of them to better understand how and when to use commas:

Rule #1: Use Commas When Writing Dates

When writing the date, commas must be used to separate days of the week, the date, and the year. For more on writing dates in English, check out our last blog post.

Example: Thursday, January 3rd

Example: October 16th, 1967

Rule #2: Use Commas When Writing City and State (or City and Country)

When writing a location, commas must be used to separate a city and state or country.

Example: Atlanta, Georgia

Example: Tokyo, Japan

Rule #3: Use Commas for Introductory Elements (Optional)

Though it is technically optional, an introductory element should be followed by a comma.

Example: Excuse me, do you know how to get to the library?

Example: Yes, I know how to get there.

Rule #4: Use Commas to Separate Quotes from the Rest of the Sentence

When writing quotations, you must use commas to separate the quote from other parts of the sentence.

Example: “I don’t like pizza,” he groaned.

Example: “Me neither,” she admitted as she stood from her chair, “let’s go somewhere else.”

Rule #5: Use Commas to Separate Additional Information

If a sentence includes additional or extraneous information, it should be separated from the rest of the sentence by commas (before and after).

Example: The teacher, Mrs. Johnson, plans to retire next week.

Example: I discovered, much to my surprise, that I got the promotion.

Rule #6: Use Commas with Dependent Clauses

When a sentence begins with a dependent clause (a clause that cannot function as a sentence on its own), it must be followed by a comma.

Example: Before I could even open my eyes, my dog was licking my face.

Example: As long as I have my morning coffee, I’m happy.

Rule #7: Don’t Use Comma Splices!

If a sentence connects two independent clauses, it will be joined by a coordinating conjunction. A comma should always precede coordinating conjunctions.

If you attempt to join two independent clauses by simply using a comma (without a coordinating conjunction), this is a grammatical error known as a “comma splice.” You can remember all of the coordinating conjunctions using the following acronym: FANBOYS (for, and, nor, but, or, yet, so).

Example: He reached the station at the correct time, yet he still missed his train.

Example: I love grapes, but I hate wine.

Rule #8: Use Commas in Lists of Three or More

If you’re writing out a list with three or more items, you will need to separate each item with a comma.

It is important to note that many dispute whether or not the final item in a list requires a serial comma (this is known as the Oxford Comma). Oxford Commas are not used in the Associated Press (AP) style of writing, though proponents of the Oxford Comma claim that it helps resolve any ambiguity.

Example with the Oxford Comma: I went to the supermarket to buy milk, eggs, and bread.

Example without the Oxford Comma: He has been to Paris, Rome, London and Amsterdam.

Creative Use of Commas

The comma rules outlined above give a clear indication of exactly how and when commas should be used. However, many writers also use commas for purposes outside of the 8 comma rules. This is the primary reason that so many English students feel confused about proper comma usage.

More specifically, commas are frequently used to denote natural pauses in speech or dramatic effect.

Example: We can find a solution, if a solution is even possible.

Grammatically speaking, the sentence above is incorrect. However, if a writer wishes to create a natural pause or dramatic emphasis, then the comma would generally be accepted as an artistic license. In literature and other works of art, the writer has some freedom to choose how to use commas.

Comma Usage and How It Affects Meaning

Remember that comma placement doesn’t only affect the grammatical accuracy of a sentence; it can also affect the meaning.

Let’s look at a few different comma placements to see how they can change the meaning of a sentence:

I love my parents, Rufus the Dog, and Fluffy the Cat.

In the sentence above, you are proclaiming your love for your parents, your dog, Rufus, and your cat, Fluffy. However, if you omit the Oxford Comma, the sentence could be misinterpreted:

I love my parents, Rufus the Dog and Fluffy the Cat.

Without the Oxford Comma, it seems like you’re saying that your parents are a dog and a cat! Here is another oft used example of why comma placement is so important:

Let’s eat, Grandpa!

Let’s eat Grandpa!

With the comma, you are simply calling your grandpa for dinner. If you take the comma away, it seems as though you plan to eat your grandpa for dinner!

Finally, here are two more comma examples:

However, you may feel (that) the story is ridiculous.

However you may feel, the story is ridiculous.

In the first sentence, the speaker is stating how they think you might feel about a story. “That” is optional in this example. However, when the comma placement is changed, the speaker is stating that the story is ridiculous, whether you think so or not.


While it may seem like you can put commas wherever you like, there are actually pretty clear cut rules governing comma usage in English.

Nonetheless, there is still some debate about certain types of comma usage (like the Oxford Comma), which can make it difficult for English students to know what is right. If you’re worried about misusing commas, simply follow the 8 rules of commas and you can’t go wrong!

To learn more about the rules of English grammar and proper comma usage, check out the Magoosh Speaking Site today!

Magoosh Team

Magoosh Team

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