Is it a, b, and c? Or...
...is it a, b and c?
The serial comma is placed after the second to last element in a series and before the coordinating conjunction (i.e., and, or, nor).
For such a little mark, there are widely diverging opinions—and conventions.
These divergences constantly results in the discriminating writer wondering whether it's correct to include or exclude the serial comma.
You see, it depends what you are writing and who you are writing for. If you are a professional writer, it's likely that you are well aware of the style guidelines for your publication.
If you are not professional, then what do you do?
In general, if you writing for academia, the serial comma is used. As an editor of both APA and Chicago, I will ensure that a serial comma is always used.
I am also aware of the ambiguity that a serial comma can cause. I will make note of this using Comments. These are rare circumstances, but they can occur. In general, a minor rewrite can solve the confusion.
Newspapers generally don't use the serial comma, which is why many casual writers are confused. They see the serial comma used or not used by dependable sources.
If you don't use styles guides, the writer or editor can choose. If you are a casual writer, you can choose! However, be consistent with your choice. Use it throughout your writing—comma predictability is like a map for your reader!
Watch this fantastic TED video that explains the serial comma debate in under 4 minutes!
Meet the Editor
I'm Coreen, and I am a copy editor, writer, instructor, digital marketer, and student of PR and Communications for organizations doing positive work in the world.