Aside from periods, commas are probably the most used punctuation marks.
Except, no one really seems to know how to use them correctly.
You get, those people, who use, them after, every other, word.
And then there are people who can write two three four five pages without ever using a comma once no matter how badly one is needed. (You have no idea how much it pained me not to use any commas in that sentence. Grammar is not something to joke about, people.)
So let’s talk about the various uses of commas and how to know when they’re needed—and when they’re not. Since commas are often called the pocket knives of punctuation (okay, I’m pretty sure no one else has called them that, ever, but I’m calling them that), they have too many uses to cover in one post. We’ll take them one by one in a series of posts, starting with the most common use:
Items in a Series
Everyone knows this one, right? Use commas to separate items in a series or list.
She put strawberries, blueberries, and bananas in the fruit salad.
BUT there may be a few things about this rule you don’t know:
1) Don’t use commas when there are only two items in a list.
She saw lions, and tigers.
She saw lions and tigers.
2) Don’t put a comma after the last item in the list.
They will go to Ireland, Portugal, or Spain, on their vacation.
They will go to Ireland, Portugal, or Spain on their vacation.
3) The final comma before the conjunction is optional.
The conjunction is the connecting word (and, or, but). Sticklers of Oxford style (I admit I am one of them) insist on the final comma before the conjunction (known as the Oxford comma). However, AP style (the style used by most newspapers and other periodicals) drops the final comma unless it is needed to avoid confusion. For the most part, unless you’re writing for a publication that follows a specific style guide, you can choose whether or not to use the final comma. Just be sure to use or not use it consistently throughout a piece. (Also, if you're writing a book, note that most of the book publishing world uses Oxford commas.)
CORRECT (Oxford style)
We have a dog, two cats, and six fish.
CORRECT (AP style)
We have a dog, two cats and six fish.
CORRECT (Oxford and AP style)
I would like to thank my children, the tooth fairy, and Santa Claus.
Let's see how that last sentence could be confusing without the final comma: I would like to thank my children, the tooth fairy and Santa Claus.
Am I thanking my children and the tooth fairy and Santa Claus? Or am I thanking my children, who are the tooth fairy and Santa Claus (wouldn’t that be an interesting family!)?
4) Items in the series must be parallel.
This does not mean that all the items in the series must run in lines that never touch. But it does mean that all the items in the series must have the same structure or be made up of the same parts of speech. If the first two items in your list are nouns, for example, the third item shouldn’t be a verb. Likewise, if the first five items follow a verb-noun format, any subsequent items in the list should follow that same format.
Examples are probably the easiest way to explain this one:
She likes kale, broccoli, and to run.
She likes kale, broccoli, and running.
See how we made that parallel by changing the verb “to run” to the noun “running”?
Let’s try another:
The monkeys hung from the trees, ate bananas, and fruit.
The monkeys hung from the trees, ate bananas, and threw fruit.
See how each item has both a verb and a noun now? Before, we didn’t know what the monkeys did with the fruit.
The monkeys hung from the trees and ate bananas and fruit.
Sometimes you don’t need a series at all. In this case, the monkeys actually only did two things: hung and ate.
You might be wondering about the fact that there are no commas in the last example at all. Shouldn’t there be one before that first “and”?
And I’ll tell you why…
Next time, when we talk about compound sentences.
Until then, I’d love to know what your biggest grammar struggles (punctuation or otherwise) are. Let me know in the comments, and you might just find a future blog post dealing with that issue. And, if you’d like help spotting and eradicating grammar errors or other issues in your own manuscript, check out my editorial services or contact me.