Consulting Journal: Writing

Writing: Serial commas

by David Blakey

Serial commas, how to use them, and whether or not to use them.

[Monday 9 January 2006]

This article is about commas, and where to put them. Most specifically, it is about serial commas, their advantages, and their uses.

There are two ways of punctuating some sentences.

I ordered eggs, ham, mushrooms, tomato, and hash browns.
I ordered eggs, ham, mushrooms, tomato and hash browns.

The first example has serial commas. The second does not. Which is correct?

The answer depends on which style manual you read. Books on business writing may advocate one or the other. Writers' style books advocate either. Newspapers' internal style guides advocate either.

The choice is not national, for a change. Most American and British publications avoid serial commas, including The Times and the New York Times. Most writers about style support serial commas, including Fowler's Modern English Usage and Strunk and White's Elements of Style.

Some authorities mandate one of the two methods. Some support flexibility, allowing the writer to choose whichever they prefer. The main point is to avoid ambiguity.

I bought sandwiches, ham, and cheese.
I bought sandwiches, ham and cheese.

The first sentence here uses serial commas. It describes my buying three items: sandwiches and ham and cheese.

The second sentence is trickier. Does it mean the same as the first sentence, or does it describe my buying two kinds of sandwiches? If my style guide stated that I would use serial commas, that would certainly remove ambiguity for me as I wrote. Deviation from the use of serial commas would indicate a special case, such as my buying two kinds of sandwiches. But how would my readers know that I applied these rules, unless they had read my style guide (and unless I had followed it properly).

In case you think that the example above is contrived, here is another.

I wish to thank my drama teachers, John Smith, and Jane Brown.
I wish to thank my drama teachers, John Smith and Jane Brown.

The first example, with serial commas, is clear. I am thanking my drama teachers and John Smith and Jane Brown. The second example is unclear.

My advice

My advice is different from that of the style guides that argue for or against serial commas. I say that you should use whichever method you want and that you should re-phrase sentences to avoid ambiguity.

One reason for this is that someone else may edit your document later and may add or delete commas, based on their personal preferences. As a result, they may introduce an ambiguity that was not there when you wrote the document. So I advise you to re-phrase not only so that you avoid ambiguity but also so that future editors cannot introduce it.

I bought sandwiches and ham and cheese.
I bought ham sandwiches and cheese sandwiches.
I bought ham and cheese sandwiches.
I wish to thank my drama teachers: John Smith and Jane Brown.
I wish to thank my drama teachers and John Smith and Jane Brown.

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