The Oxford Comma

Some use it all the time, others consider it unnecessary. Let’s discuss the Oxford comma!

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First off, a comma is a punctuation mark used for many different things, some of which are: 

• to separate items in a list (e.g. Yesterday I bought some apples, oranges, pears and a kilo of potatoes.)
• to connect clauses within a sentence (e.g. I would like to buy a new car, but I can’t afford it right now.)
• to introduce a quote (e.g. He asked, “Why do you look so tired today?”)
• to address someone directly (e.g. “Jane, can you please open the window?)

It has other functions, as well, but essentially, it’s a mark that represents a short pause in speech, and the term itself comes from the Greek work κόμμα [komma]: a cut-off piece of something.

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The Oxford comma (also known as “the serial comma”) very specifically refers to the first example given above: some like to use a comma also before the word “and” at the end of a list:

Yesterday I bought some apples, oranges, pears, and a kilo of potatoes.

This looks like such a small and trivial thing. Why should it matter if there’s a comma or not?

Well, some lists can be interpreted in different ways, based on whether a comma has been inserted or not. Compare the following:

• I invited to my birthday party my friends, Brad Pitt and Jack Nicholson. > i.e. my friends are Brad Pitt and Jack Nicholson, they are the ones I’ve invited.

• I invited to my birthday party my friends, Brad Pitt, and Jack Nicholson. > the two famous actors are not necessarily my friends, at all, I invited them in addition to my actual friends.

In other words, the Oxford comma serves to remove any ambiguity, i.e. two very different interpretations; it helps to clarify things. 

Let’s look at another example. Can you see the difference in meaning?

• Yesterday I phoned my father, a famous politician, and a close friend.

vs.

• Yesterday I phoned my father, a famous politician and a close friend.

The meaning of the first sentence is that I called three different people, one of which was my father, the other was a famous politician, while the third one was a close friend.

However, without the Oxford comma, the sense is that my father is this famous politician and a close friend. I spoke to only one person on the phone – everything after the comma is additional information about my father, not a list of three different people.

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In most cases, the use of Oxford comma is a matter of personal style and preference. Some publishers and writers use it consistently, others don’t. There’s no strict rule about it, but my advice is to use it whenever your sentence could be misinterpreted, as in the examples above. 

One thing that may persuade you to use it: there have been some very costly legal cases where the ultimate verdict depended solely on this comma (or its absence)! To find out more, click on the links below.

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ADDITIONAL READING

The commas that cost companies millions

The case of the $13 million comma and why grammarians are rejoicing

Missing Oxford Comma Leads to Million Dollar Recovery

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NOTES