Central Writing Center Handout
comma is a valuable, useful tool in a sentence because it helps the reader pause
in the right places.
DON'T MISUSE THE COMMA
in the wrong places chop ideas into wrong pieces or confuse the reader with
DON'T separate a subject from its verb!
The eighteen-year-old in California, is now considered an adult.
WRONG: The most important attribute of a ball player, is
quick reflex actions.
DON'T put a comma between two verbs!
We laid out our music and snacks, and began to study.
I turned the corner, and ran smack into a patrol
DONíT put a comma before a dependent (or subordinate)
clause when it comes after the main clause.
She was late for class, because her alarm clock was broken.
You ought to see a doctor, if you are ill.
DO USE THE COMMA CORRECTLY
help the reader to see the necessary separation between ideas within the
DO use commas to separate independent clauses when they
are joined by the coordinating conjunctions:
The game was over, but the crowd refused to leave.
commas after introductory clauses, phrases, or words that come before the main
RIGHT: Because her alarm clock was broken, she was late
If you are ill, you ought to
see a doctor.
Beginning words for starter clauses
Although, As, Because, If, Since, When, While
(While I was
eating, the cat scratched at the door.)
phrases: verb + ing
(Having finished the television program, he left the room.)
to + verb
(To get a seat,
you'd better come early.)
long prepositional phrase
(By the time he had reached the thirtieth page, he was totally
words: yes, however, well
(Well, perhaps he meant no harm.)
DO use a pair of commas in the middle of the sentence
to set off phrases, clauses, and words which are NOT essential to the meaning of the sentence.
Use one commas before to indicate the beginning of the pause and one at
the end to indicate the end of the pause.
Can you leave out the clause, phrase, or word and still have the sentence make sense?
Does the non-essential clause, phrase, or word interrupt the flow of words in the original sentence?
Can you move the non-essential element around in the sentence?
Bananas which are green are not sweet.
Bananas, which are my favorite fruit, are fattening.
A student who cheats only harms herself.
Fred, who often cheats, is just harming himself.
The girl wearing the tight sweater is attracting a lot of attention.
Prof. Benson, grinning from ear to ear, announced that the exam will be
Tom, the captain of the
team, was injured in the game.
It is up to you, Jane, to
She was, however, too tired
to make the trip.
Two hundred dollars, I
think, is sufficient.
DO use commas to separate three or more words, phrases,
and clauses written in a series.
RIGHT: She couldn't choose between John, Jim, or Joe.
RIGHT: The candidate promised to lower taxes, solve
the energy shortage,
and end unemployment.
DO use commas to separate two or more coordinate
adjectives that describe the same noun.
RIGHT: a greedy, stubborn ,easy, happy smile
DO use commas near the end of the sentence to separate
sharply contrasted coordinate elements in the sentence or indicate a distinct
RIGHT: He was merely ignorant, not stupid.
You're one of the senator's
right-hand men, aren't you?
DO use commas to set off all geographical names, items
in dates (except the months and day), addresses (except the street name and
number), and titles in names.
RIGHT: Birmingham, Alabama, gets its name from Birmingham,
July 22, 1959, was a
momentous day in his life.
Who lives at 1600
Pennsylvania Avenue, Washington, DC?
Donald B. Lake, MD, will be
the principal speaker.
DO use commas after "she said," etc. to set off direct quotations and after the first part of a quote in a sentence.
RIGHT: Julie said, "I'll see you tomorrow."
"I was able," she
answered, "to complete the assignment."
use commas anywhere in the sentence to prevent possible confusion or misreading.
RIGHT: To John, Harrison had been a sort of idol.