This is something lots of people wonder. This is something I wonder sometimes, because commas can be quite complicated, and the rules about using them very specific. So if you’re not too concerned about how to use them, let me just say this:
If you use them in writing where you’d pause when speaking, you’ll probably be fine. In a very basic way, they provide a pause for a reader, just as we give ourselves regular pauses when we speak.
But if you want to know a little more, read on…
There are quite a few rules about using commas, so I’m not going to go into a lot of depth about them, even if this is for those of you who really want to know. Mainly, it’s because most of us don’t really need to know that much about how to use them. We tend to use them correctly, as the rules are usually fairly intuitive. And even if you’re not a native speaker, the rules are fairly consistent across different languages. So you’re probably fine already. But let’s crack on, shall we?
To Separate Items in a List
Easy! Exceptions are when you need to use a semicolon for clarity, which is rarely. And of course you can throw in the Oxford Comma if you want. By the way, if you think I’m being lazy by not going into more detail about semicolons and the Oxford Comma, those two links will take you to fascinating articles I’ve already written about them.
When Starting a Sentence with a Dependent Clause
If you have trouble with commas, read this.
The part of that sentence before the comma is a dependent clause because it doesn’t work on its own: it depends on the second part for it to make sense. The second clause is independent because it can work on its own. But look at what happens if we put the independent clause first:
Read this if you have trouble with commas.
If you think in grammar terms about different types of clauses you might get confused, so forget about the terminology and say those two sentences aloud. Notice how you naturally pause after the dependent clause if you begin the sentence with if, but if you begin it with read, you don’t pause.
Note that if you separate two independent clauses with a comma, you’re guilty of using a comma splice. Like so:
He ran up to the grammar nerd, he punched him in the face.
It feels wrong, doesn’t it? Like the two should be more distinct. We can fix this in a few ways. We can simply use two sentences:
He ran up to the grammar nerd. He punched him in the face.
Or we can use a co-ordinating conjunction:
He ran up to the grammar nerd, and he punched him in the face.
Note how we still use the comma here, because the two clauses are independent (if they’re very short, feel free to omit it though).
Before or at the End of a Quotation
He said, “This grammar guy is pretty cool.”
“This grammar guy is pretty cool,” he said.
I sometimes forget this one. And if your quotation is a question, use a question mark instead of a comma.
With Certain Expressions which Begin a Sentence, or Interrupt it
Why, I can’t believe this article about commas is so interesting!
This article, by the way, is fascinating!
I don’t think I need to explain any more here, do I?
To Separate a Statement from a Question Tag
I don’t think I need to explain any more here, do I?
Between Coordinate Adjectives
Now this is where it gets a bit complicated. Remember when I told you about how we have to put adjectives in a certain order? There’s a little more to it than that. Look at these two sentences which you might use any day, repeatedly:
Niall is a tall, dark, handsome chap.
He’s drinking some delicious Spanish red wine.
Commas in the first one, but not the second one. Why? In the first sentence, the adjectives are coordinate adjectives. These means that they’re the same class of adjective, so we can order them any way we want. Dark, tall, handsome. Handsome, dark, tall. And if we wanted, we could put and between them instead of commas: Niall is tall and dark and handsome (again, this is a sentence you can use freely and regularly).
In the second sentence though, the adjectives are cumulative, which means they’re different types, and we have to put them in the right order, without commas. It’d be weird to say red Spanish delicious wine, wouldn’t it? And we also can’t use and:
He’s drinking some delicious and Spanish and red wine.
This is a good rule of thumb to figure out if you should use commas with your adjectives or not: can you use and between the adjectives? If you can, you need commas.
All the Rest
There are some other rules, but they’re pretty minor compared to the heavyweights we’ve already grappled with, so let’s just give them bullet points:
- To set off the name or term of endearment of someone you’re addressing (very old-fashioned, darling)
- To separate the day of the month from the year (3rd August, 2017), but not the month from the year! (August 2017)
- To separate a city from its country or state (Galway, Ireland)
- Before and after a title (Niall O’Donnell, MSc, is talking, shh!). Also counts for etc. and other abbreviations
- To separate contrasting parts of a sentence (We’re going here, not there!)
- If someone’s name contains Jr. or Sr., a comma should follow the surname, and also Jr./Sr. if it occurs midsentence (Martin Luther King, Jr., is one of my heroes.)
This last use of commas caused much surprise recently, like below:
People were shocked at the sheer amount of punctuation in that sentence from The New Yorker magazine. And it does look ungainly, but according to the rule above, it’s fine. The apostrophe and S do make it look longer, but they’re necessary in the sentence, and the ,Jr., makes sense for the reasons above. If you’d like to read more about, here’s The New Yorker’s explanation.
Anyway, that’s it really! There might be one or two little obscure uses of commas I haven’t covered, but the above should be more than enough to get you by. And as I said, you probably intuitively use them correctly anyway, and even if you occasionally use a comma with a cumulative adjective, no-one’s really going to notice. And the less formal your writing, the less important your use of commas is anyway. I generally use them correctly in my articles here, but if I’m writing a text message, I’ll happily use commas between independent clauses like I just don’t give a damn. Such messages are short enough that I don’t need to worry too much about the rhythm of the sentences for the reader, because there might only be one sentence in the message.
Hopefully that’s made things nice and clear, and if you have any questions, feel free to let loose in the comments. Oh, and there is one more way to use commas, but I feel like writing about that separately, so expect that tomorrow.