Commas
Punctuation and Capitalization
Commas
To get your intended meaning across to your readers, it is important that you use commas correctly, especially in the following situations.
COMMAS BETWEEN ITEMS IN A SERIES
Use commas to separate the items in a series (three or more items), including the last item in the series, which usually has and or or before it.
We can sleep in the car, stay in a motel, or camp outside.
COMMAS BETWEEN COORDINATE ADJECTIVES
Coordinate adjectives are two or more adjectives that independently modify the same noun and are separated by commas.
Conor ordered a big, fat, greasy burger.
Note that a comma is not used between the final adjective and the noun it describes.
Cumulative adjectives describe the same noun but are not separated by commas because they form a unit that describes the noun. You can identify cumulative adjectives because separating them by and does not make any sense.
The store is having its last storewide clearance sale.
[Putting and between last and storewide and between storewide and clearance would make an odd sentence: The store is having its last and storewide and clearance sale. The adjectives in the sentence are cumulative adjectives and should not be separated by commas.]
COMMAS IN COMPOUND SENTENCES
A compound sentence contains two complete sentences joined by a coordinating conjunction: and, but, for, nor, or, so, yet. Use a comma before the joining word to separate the two complete sentences.
I called my best friend, and she agreed to drive me to work.
I asked my best friend to drive me to work, but she was busy.
I can take the bus to work, or I can call another friend.
NOTE: A comma alone cannot separate two sentences. doing so creates a run-
COMMAS AFTER INTRODUCTORY WORDS
Use a comma after an introductory word, phrase, or clause. The comma lets your readers know when the main part of the sentence is starting.
| INTRODUCTORY WORD: | Yesterday, I went to the game. |
| INTRODUCTORY PHRASE: | By the way, I do not have a babysitter for tomorrow. |
| INTRODUCTORY CLAUSE: | While I waited outside, Susan went backstage. |
COMMAS AROUND APPOSITIVES AND INTERRUPTERS
An appositive comes directly before or after a noun or pronoun and renames it.
Lily, a senior, will take her nursing exam this summer.
The prices are outrageous at Beans, the local coffee shop.
An interrupter is an aside or transition that interrupts the flow of a sentence and does not affect its meaning.
My sister, incidentally, has good reasons for being late.
Her child had a fever, for example.
COMMAS AROUND ADJECTIVE CLAUSES
An adjective clause is a group of words that begins with who, which, or that; has a subject and a verb; and describes a noun right before it in a sentence.
If an adjective clause can be taken out of a sentence without completely changing the meaning of the sentence, put commas around the clause.
Beans, which is the local coffee shop, charges outrageous prices.
I complained to Mr. Kranz, who is the shop’s manager.
If an adjective clause is essential to the meaning of a sentence, do not put commas around it. You can tell whether a clause is essential by taking it out and seeing if the meaning of the sentence changes significantly, as it would if you took the clauses out of the following examples.
The only grocery store that sold good bread went out of business.
Students who do internships often improve their hiring potential.
COMMAS WITH QUOTATION MARKS
Quotation marks are used to show that you are repeating exactly what someone said. Use commas to set off the words inside quotation marks from the rest of the sentence.
“Let me see your license,” demanded the police officer.
“Did you realize,” she asked, “that you were going 80 miles per hour?”
I exclaimed, “No!”
Notice that a comma never comes directly after a quotation mark.
COMMAS IN ADDRESSES
Use commas to separate the elements of an address included in a sentence. However, do not use a comma before a zip code.
My address is 2512 Windermere Street, Jackson, Mississippi 40720.
If a sentence continues after a city-
I moved here from Detroit, Michigan, when I was eighteen.
I’ve lived at 24 Heener Street, Madison, since 1989.
COMMAS IN DATES
Separate the day from the year with a comma. If you give just the month and year, do not separate them with a comma.
My daughter was born on November 8, 2004.
The next conference is in August 2014.
If a sentence continues after the date, put a comma after the date.
On April 21, 2013, the contract will expire.
COMMAS WITH NAMES
Put a comma after (and sometimes before) the name of someone being addressed directly.
Don, I want you to come look at this.
Unfortunately, Marie, you need to finish the report by next week.
COMMAS WITH YES OR NO
Put a comma after the word yes or no in response to a question.
Yes, I believe that you are right.