Serial-Comma Rule ‑ Red, White, and Blue (2)

Comma, Comma, and Comma

When you use a coordinating conjunction (usually and or or) to join two elements of a series, no comma comes before the conjunction. But when you join three or more elements, the preferred rule requires a comma before the coordinating conjunction.

This is called the serial-comma rule. The comma is also known as the Oxford Comma.

Here’s the rule: In a series consisting of three or more elements, separate the elements by commas. When a conjunction (usually and, or, or but) joins the last two elements in the series, put a comma before the conjunction.

Comma Before the and

The serial-comma rule finds impressive support: Henry Fowler follows the rule. Strunk & White follows the rule. The Chicago Manual of Style follows the rule. Bryan Garner follows the rule. Grammar.com follows the rule.

So should you.

As we’ll learn in the eBook Developing a Powerful Writing Style and its chapter on parallel structure, the series may consist of any grammatical element. You can construct sentences with three or more subjects, verbs, direct objects, objects of prepositions, verbal objects, or any other grammatical part of a sentence.

Note: In the sentence you just finished reading, I created a series of six objects of the preposition with. A comma precedes the conjunction or, which joined the series. In that same sentence, I created a series of two adjectives (three, more) modifying the word subjects. Because the series had just two elements, no comma preceded the conjunction or, which joined the series. See how the serial-comma rule works?

In the following examples, you’ll find a variety of grammatical elements appearing in a series. Each is named parenthetically after the example.

 

Previous: Period with Parentheses or Brackets

Next: Serial-Comma Rule ‑ Examples