When you write a list of three or more items, unless you display them as a bulleted or numbered list, you conventionally separate the items with either a comma or the word ‘and’ (or sometimes ‘or’). You may choose to separate the last two items in the list with just the word ‘and’, or with a comma followed by ‘and’:
- Her shirt was red, green and blue.
- Her shirt was red, green, and blue.
If you choose the second option, you’re using the Oxford comma, also called the serial comma. This little punctuation mark arouses surprisingly strong emotions: many people will be happy to tell you that omitting the Oxford comma is simply wrong. Others will assert it is both unnecessary and ugly.
Nancy White offers a list of ten articles on the topic, with five arguing for its use, and five against. A brief search will reveal many, many more.
One argument in favour of this comma points to ‘ambiguous’ sentences like the following, taken from Steven Pinker’s book, The Sense of Style:
- Among those interviewed were Merle Haggard’s two ex-wives, Kris Kristofferson and Robert Duvall.
- This book is dedicated to my parents, Ayn Rand and God.
- Highlights of Peter Ustinov’s global tour include encounters with Nelson Mandela, an 800-year-old demigod and a dildo collector.
Another example triggered headlines around the world when a Texas schoolteacher turned it into a cartoon to illustrate the distinction between its meanings with and without the final comma.
I have two problems with all these examples:
- They are carefully constructed to appear ambiguous.
- While they are funny and clever, they don’t really demonstrate ‘why the Oxford comma is important’. Each sentence could be clarified in many other ways.
Thanks to the writer’s parents are frequently used as examples. But if I wanted to thank and name my parents, I could simply write:
I’d like to thank my parents: Max and Betty.
I’d like to thank Max and Betty, my parents.
If I wanted to thank my parents and two other people, I could write:
I’d like to thank Max, Betty and my parents.
Even if the Oxford comma is the best way to resolve ambiguity in a few, carefully constructed sentences, does that mean it should be used all the time? What’s more, in some cases the Oxford comma doesn’t remove ambiguity: Joe Kessler points out that if the Texas schoolteacher’s strippers are replaced by a single stripper, the sentence with the Oxford comma is the ambiguous one.
I prefer to avoid the Oxford comma. The trend in recent years has been towards reduced punctuation, so why use this comma anywhere it’s not really necessary? Since I write and edit primarily for the web, my lists are in any event more likely to be set off with bullets than run on within a paragraph, so the issue rarely arises for me.
In the end, your decision to Oxford comma, omit it, or use it only where required for clarity (as recommended by the Australian Style Manual) is a question of style, not substance.
So make your decision and record it on your editorial style sheet.