If a discussion of the use of commas makes your stomach churn and your head spin, then take a deep breath because there are people who not only discuss such a subject but also fiercely debate what the rules should be. A serial comma is used in a list of three or more words, phrases, or clauses to separate the items, such as in, “For Christmas, I gave my husband a cream backrub, a sinful dessert, and a vibrating chair.” The serial comma is the comma before the word and; the debate centers around the necessity of this second comma. Yes, it’s true; people really do have heartfelt discussions about this, and there are good reasons for both its use or its absence.


The contested comma goes by other names, such as the Oxford comma or the Harvard comma. It is called the Oxford comma because the Oxford University Press insists on its use as does the Harvard University Press. Numerous other style manuals require the serial comma’s use. The Publication Manual of the American Psychological Association (2010) clearly mandates a comma “between elements (including before and and or) in a series of three or more items” (p. 88). The Chicago Manual of Style (2010) also recommends using a serial comma, as do most college writing texts. On the other hand, The Associated Press Stylebook (2010), also called AP style, states that the writer should not use the serial comma in a simple series (A zebra, a jackal and an elephant visited our camp last night). The UK and Australia generally agree with AP style.


Why do so many reference books like the use of the serial comma? The most significant reason is that without the serial comma, some sentences can be ambiguous. There are several classic examples of this pitfall:

“To my parents, Ayn Rand and God”

Here, it sounds like Ayn Rand and God are your parents without the extra comma.

“We invited the strippers, JFK and Stalin.”

This sentence could mean that two strippers named JFK and Stalin will be coming to our party.


AP style might be in opposition to the serial comma use because it takes up space, is redundant, and is often unnecessary for precise meaning.  However, AP style qualifies their stance by saying that a serial comma should be used if there is obvious ambiguity.  Also, a comma is needed in a series when one item in that series uses a conjunction:

“I invited three friends, my siblings, and Mom and Dad to our Thanksgiving dinner.”


On the other hand, sometimes a serial comma can ADD confusion to the meaning of a sentence:

“To my mother, Ayn Rand, and God”

Is this giving credit to three entities:  1) my mother, 2) Ayn Rand, and 3) God?  Or is Ayn Rand my mother?  In this case, the sentence needs to be rewritten:

“To my mother and Ayn Rand and God” (Business Insider)


It should also be said that if any item in a series requires an internal comma, then semi-colons should be used instead of the series commas:

“My Dad, a preacher; my Mom, a teacher; and my husband, a banker, have taught me a great deal in life.”


Now we’re down to the crux of the issue:  to use or not to use a serial comma. First, if you are writing professionally and are required to use a particular style manual, follow the rules of that manual. Otherwise, take a stance and be consistent. AP style, the UK, and Australia may be avoiding extra spaces and unnecessary commas, but you, as a writer, may find it easiest to always insert a serial, Oxford, or Harvard comma just for consistency and clarity.



Diane Repass is a retired tenured assistant professor
from The University of Dubuque and now a beloved
writer for Plaid Swan Inc. She received her M.A. from
The University of Northern Iowa in Cedar Falls, Iowa.