USING COMMAS
NINE of the most common situations in which commas are used.
1.
COMBINING RELATED SENTENCES. Let’s say you have two sentences that could be complete
sentences all on their own, but since the ideas or actions are closely related, you would like to combine
them into one sentence. Combine them using a comma and one of the seven conjunctions—for, and, nor, but, or, yet, so—
also known as “FANBOYS”.
Sentence 1
conjunction
Sentence 2
I was skeptical and afraid, but I decided to take this course anyway.
Yesterday was her brother’s birthday, so she took him out to dinner.
He explained the assignment in detail, yet they still didn’t seem to understand.
2.
FIXING DEPENDENT CLAUSES. A dependent clause is a group of words that might look like a sentence but isn’t. Here’s
an example: Because her alarm clock was broken. The statement may look like a sentence, but it isn’t. It’s incomplete. It
doesn’t make sense. We want to ask, “What? Did she miss her first class? Did she forget to feed the cat? Was she late for
work? Did she miss the opportunity of a lifetime?” What is the answer? I guess it depends. That’s why we call it a
dependent clause; it depends on another statement to make sense. Typically, a writer will have already written the
“answer,” and the dependent clause comes just before, or sometimes right after it:
Dependent clause before: Because her alarm clock was broken. She was late to class.
Dependent clause after:
She was late to class. Because her alarm clock was broken.
This doesn’t solve the problem; the “because” statement is still incomplete. To fix this, bring the two statements together
into one statement:
Dependent clause before (comma): Because her alarm clock was broken, she was late for class.
Dependent clause after (no comma): She was late to class because her alarm clock was broken.
Words like After, Although, Because, Before, Even though, If, Since, Until, When, While, and Which
create dependent clauses. Don’t let them stand alone. Combine them with the “answer” statement.
Dependent clause before (comma needed)
If you are ill, you ought to see a doctor.
When the snow stops falling, we’ll shovel the
driveway.
While I was eating, the cat scratched at the door.
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Dependent clause after (comma not needed)
You ought to see a doctor if you are ill.
We’ll shovel the driveway when the snow stops falling.
The cat scratched at the door while I was eating.
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3. LISTING THREE OR MORE THINGS OR ACTIONS IN ONE SENTENCE.
The constitution establishes the legislative, executive, and judicial branches of the government.
Joey walked into the room, sat down, took out his books, and shook his head.
The best things in life are laughing with family, meeting new friends, accepting challenges, and eating ice cream.
4. AFTER INTRODUCTORY WORDS such as However, Therefore, Well, Yes.
However, Cleveland Brown was never fully accepted by the gang in Quohaug.
Therefore, Stewie concluded that Lois must be eliminated.
Well, cases like this usually go to trial.
Yes, your loan will probably be approved.
5. SEPARATING EXTRA INFORMATION that interrupts the flow of a sentence. Sometimes you want to add some extra
information or description to a sentence. But that can interrupt the flow of a sentence, so use a comma on both sides of
the extra information to separate it from the main sentence.
David Smith, who is a junior, won first place.
Fred, who often cheats, is just harming himself.
Apples, my favorite fruit, are the main ingredient in this recipe.
My dad, Mauricio “Shogun” Rua, made his living as a mixed-martial arts fighter.
6. SEPARATING THE NAMES OF PLACES AND SEPARATING DATES, ADDRESSES, AND TITLES IN NAMES.
Birmingham, Alabama, gets its name from Birmingham, England.
July 4, 1776, is an important date.
The President lives at 1600 Pennsylvania Avenue, Washington, DC.
Rachel B. Lake, MD, will be the principal speaker.
7. SEPARATING CONTRASTING IDEAS IN A SENTENCE.
8. USING TWO OR MORE ADJECTIVES TO DESCRIBE SOMETHING.
He was merely ignorant, not stupid.
She has an easy, happy smile.
She is a lawyer, not a doctor.
The big, red, smelly, old truck.
The chimpanzee seemed reflective, almost human.
9. WRITING DIALOGUE.
John said, “I’ll see you tomorrow.”
It’s odd,” Billy said, “to see the farm again.”
Nothing in life is ever easy,” he told me.
“I was able,” she answered, “to complete the assignment.”