Unlike the hipster semicolon, the misunderstood colon, and the purposely avoided dash (both the en- and em- variety), the comma is used every day, all the time, by everyone. But who’s actually using it correctly?
Let’s stop guessing. Here is a list of when and how to use a comma (in no particular order):
1. To separate complete sentences when they are joined together by FANBOYS (for, and, nor, but, or, yet, so)
- For their trip to London, Jo is responsible for planning the itinerary, and her sister is in charge of making hotel reservations.
- Next week is my sister’s 16th birthday, so we’re planning something special.
- G-DRAGON is Korean, but Gerard Way is American.
2. After introductory phrases but before the main clause
a. Words in introductory clauses that should be followed by a comma include after, although, as, because, if, since, when, and while:
- Although it was raining, Jo went out for a jog.
- Because he always asks intelligent questions, Mike is the teacher’s pet.
- If you want to get a good score on the paper, don’t procrastinate.
b. Introductory phrases such as participial and infinitive phrases, nonessential appositive phrases, and long prepositional phrases should be followed by a comma:
- To meet the popular singer, you should come to the concert three hours early.
- Having eaten a hearty breakfast, the lumberjack went to work.
- After a tough day at work, Jo relaxed by taking a long bath.
c. Introductory words such as yes, however, and well should be followed by a comma:
- However, the computer didn’t have enough memory to run the program.
- Yes, I would like to take a nap.
- Well, Goku and Krillin are just fictional characters.
3. To separate three or more words, phrases, or clauses expressed as a series
- When Jo goes to the market, she always buys milk, eggs, and coffee.
- My sister promised to clean the bathroom, take out the trash, and wash the car.
- The coach demanded that the star player be at practice on time, be a good example to rookies, and be the face of the franchise.
NOTE: In this article, we won’t go into the debate about whether the Oxford comma (the last comma in a list of three or more things) is necessary. If you’re curious about this topic, you can read our Tumblr post.
4. To set off clauses, phrases and words in the middle of a sentence that are not essential to the meaning (e.g., nevertheless, however, after all, by the way)
- I am, by the way, unqualified for the position you’re offering me.
- The job, however, does pay well and come with exceptional benefits.
- The company, after all, is renowned for the way it treats its employees.
5. To set the name, nickname, or title of a person to whom you’re talking
- Do you, Jo, take Mike to be your lawfully wedded husband?
- Good night, Dad.
6. To separate a city from its state
- Jo currently lives in Los Angeles, California, with her dog.
- Our entire family resides in the Denver, Colorado, area.
7. (Optional) Before Sr. or Jr. in a person’s name
- Albert Hammond, Jr. is the guitarist of The Strokes. = Albert Hammond Jr. is the guitarist of The Strokes.
Although the comma before Jr. or Sr. is optional, if you to choose to use it, you must also use a comma afterward:
- Albert Hammond Jr. has arrived. (Right)
- Albert Hammond, Jr., has arrived. (Right)
- Albert Hammond, Jr. has arrived. (Wrong)
8. To set off nonessential elements of a sentence, i.e., not phrases that begin with “that” (restrictive clauses)
Do NOT use a comma before the “that” phrase:
- The game that features Lionel Messi on its cover costs $59.
- The book that I borrowed from the library is missing 30 pages.
Use a comma before the following nonessential elements (set off by commas):
- Jo, an adventurous girl, is taking skydiving lessons.
- My twin sister, who forgot to do her homework, had to stay after school to complete it.
- Gerard Way, covering his eyes with his hands, sat in his favorite chair.
For more on restrictive and non-restrictive clauses, read this Tumblr post.
9. To separate two or more coordinate adjectives that describe the same noun
Coordinate adjectives have equal status in describing the noun. If this sounds confusing, you can ask two questions to figure out if two adjectives in a row are coordinate:
- Does the sentence work—and mean the same thing—if the adjectives are written in reverse order?
- Does the sentence work—and mean the same thing—if the adjectives are written with and between them?
If the answer is yes, then you’re dealing with coordinate adjectives. They should be separated by a comma.
- My little brother is a loud, obnoxious child. (It works with “loud and obnoxious,” so they’re coordinate adjectives.)
- Jo often wears a blue wool sweater. (It doesn’t work with “blue and wool,” so they don’t need a comma.)
- Your niece has a bright, happy smile. (It works with “bright and happy,” so they’re coordinate adjectives.)
10. Near the end of a sentence to indicate a pause, shift, or contrast
- The protagonist was merely asleep, not dead.
- The robot seemed compassionate, almost human.
- You’ll be coming to the party tonight, right?
11. To separate the day of the month from the year
Don’t forget to also put a comma after the year!
- We found a typo in the newspaper’s January 3, 2014, edition.
If you’re just writing the month and year, you don’t need a comma:
- Do you have the May 2013 issue of the magazine?
12. To introduce or interrupt direct quotations
- He screamed, “I don’t care!”
- “When,” Jo asked, “will you fix my car?”
If it’s a one-word quotation, the comma is optional:
- I said “Yes.”
We also use a comma if the quote is stated first; in this format, a comma is required even for one-word quotations:
- “I don’t want to hear your excuse,” he said.
- “Stop,” Jo said.
13. Before and after certain introductory words, such as “namely,” “that is,” “i.e.,” “e.g.,” and “for instance”
- You will be told to bring numerous school supplies, e.g., pencils, erasers, rulers, notebooks, and staples.
- Jo loves K-pop groups, namely BIGBANG, 2NE1, Girls’ Generation, and Super Junior.
For more on i.e. and e.g., read this Tumblr post.
14. Before “etc.”
- In the refrigerator, you will find eggs, milk, cheese, etc.
If etc. appears in the middle of the sentence, it should be enclosed with commas:
- You will find eggs, milk, cheese, etc., in the refrigerator.
- This sentence will conclude, end, close, etc., this article.