The Oxford comma is the comma that precedes the conjunction before the final item in a list of three or more items:
- This song is dedicated to Moe, Larry, and Curly.
- This website is dedicated to Moe, Larry, Curly, Shemp, Joe, and Curly Joe.
- This book is dedicated to my roommates, Nicole Kidman, and God.
When Should We Use the Oxford Comma?
Most U.S. style guides say, "Use it--always." Garner's American Usage (Oxford, 2009) makes the standard case for clarity:
Whether to include the serial comma has sparked many arguments. But it's easily answered in favor of inclusion because omitting the final comma may cause ambiguities, whereas including it never will.Likewise, The Chicago Manual of Style (2010) "strongly recommends" using the serial comma because "it prevents ambiguity":
If the last element consists of a pair joined by and, the pair should still be preceded by a serial comma and the first and:Most college writing handbooks in the U.S. also advocate use of the serial comma.
- The meal consisted of soup, salad, and macaroni and cheese.
- John was working, Jean was resting, and Alan was running errands and furnishing food.
But not The Associated Press Stylebook (2010), which determines usage at most American newspapers:
Use commas to separate items in a series, but do not put a comma before the conjunction in a simple series: The flag is red, white and blue. He would nominate Tom, Dick or Harry.But the AP Stylebook (which is always looking for excuses to save space) does qualify this precept:
Put a comma before the concluding conjunction in a series, however, if an integral element of the series requires a conjunction: I had orange juice, toast, and ham and eggs for breakfast.Most British and Australian style guides also discourage use of the serial comma in simple lists, allowing it only "when its omission might either give rise to ambiguity or cause the last word or phrase to be construed with a preposition in the preceding phrase" (Australian Government's Style Manual for Authors, Editors and Printers).
Use a comma also before the concluding conjunction in a complex series of phrases: The main points to consider are whether the athletes are skillful enough to compete, whether they have the stamina to endure the training, and whether they have the proper mental attitude.
Final Comments on the Oxford Comma
What is our advice? Unless you're writing for an American newspaper, living in the U.K. or Australia, or leading a campaign against superfluous punctuation, use the serial comma--or the Oxford comma or the Harvard comma.