How to Use Serial Commas in Sentences

A serial comma is a comma that separates the last two items in a list, appearing before the "and" or the "or" in the list. Though not all styles of writing use the serial comma, it's standard in academic writing. It can also help you better clarify your meaning of list items including "and" or "or."

Instructions

1. Insert a comma before "and" or "or" whenever you include a list of three or more items in your writing, unless the style rules you're following explicitly state that you shouldn't. This is the basic rule of the serial comma.

2. Use care with the serial comma when you have more complex lists or lists that readers can easily misunderstand. For example, the meaning of this apocryphal dedication changes depending on where you place the serial comma: "To my parents, Ayn Rand and God." Without the serial comma before "and," it sounds like the writer may be saying that Ayn Rand and God are her parents.

3. Leave out the serial comma if you only have two items in a list. A serial comma only belongs in a list of three or more items.

4. Replace the serial comma with a semicolon if you're presenting a list in which the items contain commas. Follow the same rules for using a semicolon as you do for the serial comma.

5. Check your writing for consistency with regards to serial commas. If you use a serial comma in one list, make sure you use them in all lists. Either approach is technically correct, but going between the two approaches isn't.

Tips & Warnings

• The serial comma is also known as the Oxford or Harvard comma.

• Most journalism styles omit the serial comma, so you rarely see it used in newspapers.