How to Use a Comma to Separate Three or More Items

There are many different uses for commas. Sometimes, the rules for these uses can be somewhat flexible. Fortunately, the rules for using commas in a list are straightforward. The only time the rules change are when you're writing in a style that requests you don't use a serial comma, such as Associated Press (AP) style.

Instructions

1. Use a comma to separate three or more items in a list. Use a comma right before the conjunction in your list. For example, "She bought butter, milk, and bread from the grocery store" or "The traffic signal can only light up red, yellow, or green." The last comma in these examples is known as the serial comma.

2. Use commas to separate three or more phrases or clauses in a sentence. For example, "Today, Bill picked up his suit at the dry cleaners, took a bike ride through the park, and cooked steak for dinner."

3. Eliminate the serial comma when writing in certain styles. There are some styles of writing where you don't use the serial comma. The earlier examples would look like this without serial commas: "She bought butter, milk and bread from the grocery store," "The traffic signal can only light up red, yellow or green" and "Today, Bill picked up his suit at the dry cleaners, took a bike ride through the park and cooked steak for dinner."

References

• owl.english.purdue.edu: Extended Rules for Using Commas; by Dana Driscoll and Allen Brizee; Nov. 16, 2010