A minor quibble, not a matter of international import, merely enough to provoke the occasional fit of inappropriate rage: I am sick of well-meaning people, unaware of their own blinkered knowledge of the many standards of global English, pointing out what they believe is the grammatical howler of a writer having omitted the Oxford comma.
What is the Oxford comma, also known as the serial comma? It’s a little thing, like half a pig’s tail. In a list of three or more items, most Americans and some of the British include a comma before the “and” (or “or”) preceding the last item. For example, if such a person wanted to list “rage”, “apoplexy” and “sadness”, they would write rage, apoplexy, and sadness. The difference is merely that comma before the “and”.
Use it or don’t use it; for the most part, it’s mind-numbingly unimportant. Neither form—with or without the extra comma—is more or less correct. It is a custom, and only a custom, that differs by country, by institution and by person. It is not some rule of usage prefaced upon inviolable linguistic laws discovered once the human genome was decoded. Dealer’s preference.
And yet it is so very common to receive straight-faced correctives, often from Americans, telling one they have erred for want of an Oxford comma. Such mindless prescriptivism is maddening. It shouldn’t be, but the contradiction inherent in the act just sets off a certain kind of person (that person would be me).
As for what the conscientious writer should do—that is, a writer not bound by custom and merely looking to maximise clarity and readability—there tend to be two main arguments put forth, one from each camp.
Those who discourage use of the Oxford comma point out that it is normally redundant. They are right, from the perspectives of both syntax and prosody. The “and” that comes before the last item in a list alerts the reader that it is the last item in the list (this is the syntactic function, concerned with arranging the units of meaning in a sentence). Likewise, the “and” encourages, or arguably necessitates, some sort of pause or change of rhythm as the sentence is read (this is the prosodic function, concerned with regulating the rhythm and melody of a sentence).
In this sense, then, the Oxford comma is heavy-handed. Writers are often encouraged to eschew surplusage, and the Oxford comma is nearly always, strictly-speaking, surplus to the minimum required to convey one’s meaning.
But not always. Sometimes a list becomes confusing without that extra comma. If I want to list the big boys, Jack and Jim without using an Oxford comma, you cannot tell whether I mean three things (big boys, Jack, Jim) or if I’m just referring to the big boys, who are named Jack and Jim. No such problem with the trusty Oxford comma in the mix: the big boys, Jack, and Jim. So, there is no doubt, an Oxford comma should be in every writer’s arsenal.
However, to say that just because it is useful once in a blue moon every writer should use an Oxford comma in every list they write across their lifetime—we’re talking tens of thousands of lists, tens of thousands of redundant commas—is silly. It’s just getting suckered into the prescriptivist mentality: we have to have a hard and fast rule! There can be no discretion! Man and woman are not responsible enough to make their own decisions about when a comma is necessary! Yes, dammit, we will have hundreds of millions and very soon billions of redundant commas to ensure no one misses that rare occasion when it is actually needed!
Dear oh dear, the grammar nanny state, the most minor of all the dystopias.
My suggestion for those who can’t just live and let live, who are seeking some sort of guidance on this pressing matter of comma security: go with discretion. Trust the writer to use that comma when and only when it is required for clarity.
I work as an editor for living, and that’s my policy. Mostly no Oxford commas, but I’ll throw one in every blue moon when it means the reader does not have to slow down too much or reread the passage to be sure of the author’s intended meaning. And if a writer does get the exercise of their discretion wrong—if they write a list without an Oxford comma and that causes some sort of confusion—point it out and put one in. Otherwise, shut up, piss off and leave me and my commas alone.