University of South Carolina

COMMAS

 

In using commas, writers often take the litterbug approach: dropping commas on their papers, hoping that they won't be noticed if they have been used incorrectly. Actually, comma rules are quite simple. Master the following basic rules and the few special-occasion rules, and you will never have to litter your paper with commas again.

The Basics

1. Separate three or more words

She plays volleyball, lacrosse, squash, and tennis.

2. Separate three or more phrases

He went down the hill, around the corner, but not into the house.

3. Separate three or more clauses

We cannot decide if we're going to the party, if we're going to 
the movies, or if we're staying home.

Note: the clauses begin with “if”

4. Separate coordinate adjectives preceding a noun

The narrow, winding road is especially hazardous in winter.

Note: Coordinate adjectives work together to describe the noun

5. Separate two sentences joined by a coordinating conjunction

She went to work, so he went home. 
She went to work, but he went home.

Note: Coordinate conjunctions help two complete sentences make sense together. Use the word FANBOYS to remember the common coordinating conjunctions: for, and, nor, but, or, yet, so.

6. Set off introductory phrases or clauses in a sentence

At the end of the year, we celebrate the death of the old and the birth of the new. 
Walking down the street, Maria found a new penny.
 
Although it's raining, we're still going to the fair.

Note: To be sure that you need a comma, look at what happens if you delete the introductory words (before the comma) from the sentence. You should have a complete sentence left after the comma.

7. Set off non-restrictive elements in a sentence

The dog wagged his tail, which he broke last week. 
Everyone who is late will be penalized.

Note: Here, think of the commas as weak parentheses. Non-restrictive means that the elements do not need to be in the sentence--they provide extra or helpful information to the reader. To check that you need a comma, omit the word or words and see if the meaning of the sentence remains clear and unchanged.

8. Set off contrasting phrases

I play squash, not tennis. 
Time, not money, is the most important thing to spend on children.

Some Special Occasions

9. Set off interjections, names used in direct address, and tag questions

Finals week is, alas, a horrible time for me.
Ari, do we need to study together tonight?
We need to study for at least three hours, don't we?

10. Set off non-restrictive appositives

"The Bells," by E. A. Poe, is one of my favorites.
My son, Russ, has black hair. 
Shana Troy, who was elected mayor, is my boss.

Note: Appositives are words that are not needed to identify the noun they modify

11. To show omission

One plant in our town makes cars; another, furniture.

12. In dates

November 7, 1896, is my grandmother's birth date.

Note the comma after the year

13. In letters

Dear Alanni, 
Sincerely,

14. In addresses

We live at 100 New Street, Oak Tree, Ohio 00000. 
One-hundred New Street, Oak Tree, Ohio 00000, is our new address.

Note that there is no comma between the state and the ZIP code

15. With quotations

Lucy said, "No, I cannot go with you."
"No," Lucy said, "I cannot go with you."
"No, I cannot go with you," said Lucy.

You are welcome to bring a draft of your paper to the Writing Center for more help. Call 777-2078 for an appointment or for more information.