Series Commas: The Comma Before "And"

The use of the serial comma (also called the series comma, the Oxford comma, the Harvard comma, or simply the comma before and) is a debated issue in American writing. One single authority, and a few authors, claim the comma before and is unnecessary ... unless it's necessary for clarity. Then try to remember to use it. All other American authorities say, clearly and simply, use the serial comma!

For one, it is never confusing to have the comma before the last item in a series, where it is frequently confusing to have it missing. For another, even if the author thinks the series is clear without the comma, the reader may encounter a clarity bump that could have been avoided with the simple stroke of a key. And for final, it is easier to always use it even when it is not necessary for clarity than to try to remember to use it when it is necessary for clarity.

Are there cases where the meaning of a series is perfectly clear without the serial comma? Of course there are. But even when it is clear without the comma before and, it is good practice to be consistent, so that you don't eliminate the comma in a situation where it is really needed. In addition, if you are not in the habit of using the series comma, it is all too easy to overlook an instance when your series is not at all clear. After all, as the writer, you know what you mean; and since even when you proofread you will still (one hopes) know what you meant, unless you are a careful and consistent proofreader, you'll skip right past the confusing part, leave the comma out, and leave your reader to flounder for your meaning.

For a somewhat ridiculous example to illustrate the point, what would you like for lunch? We have ham and cheese, peanut butter and jelly and watercress and mayonnaise sandwiches. Now, doesn't that sound appetizing?

It's a single keystroke. The vast majority of us are not writing a newsletter or journal where space is at such a premium that a weensy little comma would make any difference. And yet, that weensy little comma can make a great deal of difference to your reader, especially if you are not as crystal clear as perhaps you think you are in your writing style. So ... why not just add the serial comma?