University of Louisville
Yield to the Comma
1. Commas go between items in a list or series.
Example: Please put your notebooks, backpacks, and cell phones away.
Some publications omit the comma between the last two items of the series, but sometimes that can cause confusion in reading.
Example with final comma omitted: Her favorite breakfast foods are
biscuits and gravy, pancakes with syrup and eggs.
Example with final comma: Her favorite breakfast foods are biscuits and
gravy, pancakes with syrup, and eggs.
2. Commas go between descriptive words when each of them describe the noun that follows.
Example: The dog had long, red, shiny fur. (The dog’s fur is long and red
Commas do not go between descriptive words that do not each describe the noun that follows them. Rather, one descriptive word describes the word immediately following it.
Example: Her aunt wore a bright green coat. (The coat was not bright;
the color was bright green)
3. Commas go after many introductory words, phrases, and clauses.
Example: In fact, he has been feeling depressed since he lost his job.
Example: Because Sarah had skated all day, her feet were sore.
Example: Reviewing the research on the economy, I found that the
building industry was declining all over the world.
Example: In the big park across from my daughter’s school, the dogwood
trees are blooming.
Such phrases and clauses at the end of sentences are not set off by commas.
Example: Sarah’s feet were sore because she had skated all day.
4. Commas go around a phrase that is not essential to the meaning of a sentence. A sentence still makes sense without it.
Example: His biology test, which was very difficult, covered the last six
chapters of the textbook.
(His biology test covered the last six chapters of the textbook.)
Example: My father, an English professor, teaches at the University of
(My father teaches at the University of Louisville.)
5. Commas go before words such as for, or, nor, and, so, but, yet when they join two main parts of a sentence—either of which could be a complete sentence by itself. Do not use a comma before such words when they join parts of a sentence that cannot stand alone as complete sentences.
Example: They stayed up all night, so everyone was really tired
for class in the morning.
Example: Tomorrow I’m supposed to go to work, but I think I’ll write my
Example: Martha finished cooking dinner and then sat down to read the
paper. (no comma)
6. Commas go before or after quotations unless the quoted words become a part of your own sentence. Do not use commas to tell something someone said if you are not quoting the person directly.
Example: William Shakespeare said, “To thine own self be true.”
Example: “Go to bed,” he told me, “or you won’t want to get up in the
Example: “That’s my very favorite song,” she stated.
Example: April may be the “cruelest month” to T.S. Eliot, but it is my
favorite. (No commas around the quotation)
Example: John told me that he would be out of town for a week. (No
7. When addressing someone by name, commas go after the name. Commas are also used after titles associated with names.
Example: John, tie your shoes.
Example: Martin Luther King, Jr., initiated the bus boycott in
When giving a full date (day, date, year), use commas after both the day and the year. Commas also go after both city and state when they are part of a sentence.
Example: He said his birthday was April 1, 1776, but he’s trying to fool
Example: We are going to San Francisco, California, on our vacation.
8. Commas are used in numbers of four or more digits (exceptions: do not use commas in zip codes, phone numbers, street numbers or years)
Examples: 3, 500 10, 801 456, 978
Do not use commas alone to connect two complete sentences. That is called a comma splice. Either create two separate sentences, or combine sentences with connecting words using the rules listed above.
Example: Bob went outside to mow the lawn. Jane played the piano in the
Example: Bob went outside to mow the lawn, but Jane played the piano in
Example: While Bob went outside to mow the lawn, Jane played the piano
in the house.
Example: Jane played the piano in the house while Bob went outside to
mow the lawn.
Kirstin L. Krumsee
September 27, 2007
Rev. April 22, 2009
Samantha Long, Ashton Moats,
Beth Mohon, Ruth Miller