You are responsible for using four types of commas and their rules correctly in your writing. When you’re wondering if you should use a comma, check it against these rules to determine if you need one and where it should go.
A sentence with an introducer comma starts with a word, phrase, or clause that introduces the main idea of the sentence. The information before the comma is NOT a complete sentence, while the information that follows the comma should be. The introducer has three rules.
- Use an introducer comma after an introductory word or mild interjection.
Well, how did the audition go?
Hey, I heard she got the part.
Yes, she was very excited.
- Use an introducer comma after nouns of direct address.
Ms. Henderhan, is this the proper way to use an introducer comma?
Class, this is rule number 2.
- Use an introducer comma after introductory phrases or clauses.
Remember, the information before the comma is NOT a complete sentence.
After the game, we’re going out to dinner.
When I get home, I’m going to watch Lost.
Running through the snow, I left crisp footprints for my friends to follow.
Use a coordinator comma to join two complete sentences. The sentences are connected with a coordinating conjunction and a coordinator comma.
The coordinating conjunctions are FOR AND NOR BUT OR YET and SO.
The comma comes before the conjunction.
I went to the store, and I bought a new umbrella.
It was raining, but it stopped before I had the umbrella open.
The sun came out, so I put the umbrella away.
Check for two conditions before using the coordinator comma:
- The sentence contains two complete ideas.
(a subject and a verb on each side of the comma)
- They are connected with a coordinating conjunction.
Linker commas are used to link ideas together. The linker comma has three rules.
- Use a linker comma to link three or more items in a series.
These include words, phrases, or clauses.
My cats are named Ennui, Grumble, and Smokes. (words)
They like to play with catnip, run outside, and sleep on our laps. (phrases)
Ennui is the oldest, Grumble is the smallest, and Smokes is the furriest. (clauses)
- Use a linker comma to link together adjectives that describe the same noun.
Smokes is a big, fluffy, gray cat.
Ennui is a fat, black, lovable feline.
The skinny, aloof, tiger-striped cat is Grumble.
It was a bright red apple. (bright describes red, not apple, so no linker comma here.)
- Use a linker comma to link on additional information or afterthoughts. The information before the comma is a complete sentence, while the information after the comma is not.
I went straight to bed, tired from a busy day.
He watched as his friends left for the movie, wishing he had done his homework.
Use a pair of interrupter commas to set off non-essential or additional information from the main idea of the sentence.
Think of the interrupter commas as handles. If you can lift the information between the commas out and still have a complete sentence left, you’ve used them correctly.
Ms. Henderhan, the yearbook adviser, worked on her high college yearbook.
Halloween, my favorite holiday, is celebrated on October 31.
Monday night, when I go to class, I get home very late.
Don’t use interrupter commas if the information is necessary to the sentence.
The movie Holes is based on a novel by the same name.
Chess and gaming adviser Mr. Bowen is an accomplished gamer himself.
Media Specialist Mrs. Ibach is a very knowledgeable lady.