Our Friend the Comma,
The comma is a piece of punctuation that prompts readers to take a pause in the middle of a sentence. The comma also works to separate things into lists.
Here are five of the most common ways to use a comma:
1. For the purpose of joining independent clauses
Independent clauses are separate word phrases that can be understood as two different sentences. A comma will go in front of the coordinating conjunction- the word that joins the two independent clauses. Coordinating conjunctions include and, but, or, nor, for, so, and yet.
Example:
We went to the Apple Bee's across the street from the park, but I didn't have a chance to go feed the ducks.
Exception: If the independent clauses are short and easy to understand, it is not necessary to use a comma.
We went to the Dairy Queen but I don't like ice cream.
2. For use after an introductory clause or phrase
Introductory phrases sometimes function as adverbs and usually tell when, where, how, or why.
The comma tells a reader that the preliminary part of the sentence has begun and the second part has begun.
Example:
In the bottom of the trash in the potato peelings, we found my lost ring.
Exception:
A comma is not necessary if after a simple phrase there is no danger of misreading the sentence.
In a short time we drove to Chicago.
3. To separate items in a series
If three or more items are in a list, a comma is necessary to separate them.
We invited Cindy, Nick, JoAnna, Erica, and Darko to the party.
4. To join coordinate adjectives that are not joined by and
Coordinating adjectives can be rearranged in the sentence and need to be separated with a comma.
Danny is a kind, caring, sensitive friend.
Cumulative adjectives cannot be rearranged in the sentence. Do not put a comma in between these kind of adjectives.
Our wedding cake is a five layer rich chocolate masterpiece.
5. To set off transitional and parenthetical expressions, elements expressing contrast and absolute phrases
Transitional expressions help connect parts of sentences. The most common transitional expressions are conjunctive adverbs that include: however, therefore, and moreover. Other phrases include for example, as a matter of fact, and in other words.
Example:
For example, this is a good time to use a comma.
Here are some other ways to use a comma
7. To prevent confusion
Sometimes if a sentence is worded in a certain way, it needs a pause to make sense. A comma will tell a reader to take a pause.
Example:
If you cook the cat will come. ---- We don't want to cook the cat.
If you cook, the cat will come.
8. For use with expression
Commas can also be used to indicate that a quote is coming. Use a comma after a statement like she said and just before quotes.
Example:
Mr. Rogers said, "Won't you be my neighbor?"
9. For use with dates, titles and numbers
Commas need to be used to set off certain information
Dates:
On April 23, 1981, I was born.
Addresses: Commas belong in between elements of addresses except zip codes.
I was born in Sylvania, Ohio.
Titles:
Janice Milford, M.D., was the doctor who delivered me
Numbers: Commas separate numbers that are more than four digits long into groups of three.
I bet on the same day I was born, at least 20,234 other kids were born too.