People who work with words like to argue about the rules of grammar and punctuation. Some people really get angry over rules against split infinitives and dangling modifiers. It’s a little sad, when you think about it.
One of the big argument-starters is the serial comma. Sometimes it’s called the Oxford comma because it’s the official style of the Oxford University Press.
An Oxford fan will put a comma between the final two items in a series: dog, cat, and mouse. Arguments in favor of this rule include the fact that Oxford knows much more about these things than you do, dear child. Also, the final comma is all that stands between civilization and anarchy.
But not everyone roots for Team Oxford. The opposing camp includes the Associated Press, which is the style followed by most newspapers and magazines. AP style says there’s no need for a comma when you already have an “and” between the final two items. After all, you wouldn’t write “cat, and mouse.” Why change everything when you add the dog?
The arguments usually escalate from there. Lips are pursed. Noses are raised in the air. When one side starts calling the other prissy or uncultured, I usually set down my cup of tea and leave the room. I have enough turmoil in my life already.
Fortunately, you don’t have to be a slave to either rule. As long as you are consistent, your readers should have no trouble understanding a truly simple series with or without the Oxford comma. When the series isn’t so simple, neither rule will automatically keep you out of trouble. The good folks at Mental Floss have compiled some fine examples of the pitfalls with and without that last pesky comma.
Instead of slavishly following the rules and declaring your job complete, read your sentences with a skeptical eye. If there’s any ambiguity in a sentence, rewrite it. Change the order of the words. Split a long, convoluted sentence into two shorter ones. Break out the semicolons. There are plenty of ways to smooth out a sentence and keep your readers from stumbling.
Following the rules is never an excuse for muddled writing.