The Oxford Comma

I’ve visited France, Germany and Spain this year.

I’ve visited France, Germany, and Spain this year.

You probably don’t see any difference between the above pair of sentences. But what about this pair:

On Twitter I’m following my friends, Stephen Fry, and Miley Cyrus.

On Twitter I’m following my friends, Stephen Fry and Miley Cyrus.

The second sentence is quite ambiguous. Do I mean that I follow my friends on Twitter, in addition to the celebrities Stephen Fry and Miley Cyrus? Or do I mean to say that Stephen Fry and Miley Cyrus are my friends, and I follow them on Twitter? The latter would probably make for some interesting dinner-party conversations, but that’s probably not what I meant, is it?

Still, just to be sure my meaning is clear, I can use the first sentence, with the comma between Stephen Fry and Miley Cyrus. A comma like this, before the last item in a list of three or more items, is known as the Oxford comma, as it’s an element of the house style of Oxford University Press. There’s quite a bit of debate about whether or not to use the Oxford comma, and it has its strong supporters as well as determined detractors. Some style guides recommend its use, some suggest avoiding it, and others don’t mention it at all.

Why use it? As we see above, it can resolve ambiguity in cases where the first item in a list might seem like it’s referring to the second and third items. More generally, it can avoid ambiguity when two words in a list could be joined together as one item, or could be separate items. For example: Continue reading