Oxford Comma!Before I start my post, I want to apologize for a lack of posts over the past few days. I had my commencement ceremony this week and will be starting graduate school this Monday; I’m sure you can imagine how hectic these past few days have been.

In what-seems-like-a-decade-ago, I wrote Part 1 of the Comma Series. That post covered the use of commas with coordinating conjunctions. It can be found here. Today’s section of the Comma Series will illustrate the “Oxford Comma.” I know I promised Adverbial Conjunctions, but I’m pretty tired at the moment and am not up to the task of teaching adverbial conjunctions! So if you don’t know what an “Oxford Comma” is, make sure you keep reading!

What is the “Oxford Comma?”

Well its proper name is “serial comma,” but I think “Oxford comma” sounds much better–don’t you? :-D This comma is relatively controversial because there’s no real rule on whether or not you should use it. In some cases, it can help you. In others, it can hinder your meaning. Let’s see what it is.

When listing items, you have to put some sort of conjunction in to connect them. This conjunction is most frequently “and” or “or.” You may place a comma after the last item that comes before the conjunction. For example, “I need to go get apples, grapes, oranges(,) and pears.” See that comma in the parenthesis? That’s the comma I’m talking about.

Now what?

Well let’s look at the above example, removing the comma this time. “I need to go get apples, grapes, oranges and pears.” This one isn’t TOO confusing, but let’s look at how these items break down with and without the comma:

No comma: I need to get (apples,) (grapes,) (oranges and pears.)
Comma: I need to get (apples,) (grapes,) (oranges,) and (pears.)

Notice in my first example, oranges and pears are lumped together. This could mean a mix of oranges and pears (like a fruit cup or fruit salad). In the second example, the oranges and pears are separated into individual items.

Let’s look at a much more ambiguous example: “I like oatmeal, gingerbread, peanut butter and jelly and chocolate chip cookies.” Notice I omitted the comma here. Let’s see how this one appears:

No comma: I like (oatmeal,) (gingerbread,) (peanut butter and jelly and chocolate chip) cookies.
Comma: I like (oatmeal,) (gingerbread,) (peanut butter and jelly,) and (chocolate chip) cookies.

For this example, the comma is pretty important. The comma is controversial because in some cases, the comma can confuse the sentence and in other cases it can clear ambiguity.

Final thoughts

The serial comma can be somewhat tricky. You only need it when you’re listing three or more items. I generally use it all the time unless it makes the sentence difficult to understand. Think about how your sentence breaks down with and without the comma, and then choose accordingly. Good luck!