Most people are confused when it comes to commas - because it feels like there is always an exception to any given comma rule. The thing is, it’s really very easy if you know the core rules.
The 9 Ways to Use a Comma
I don’t like to say things like always and never, but if you know the essential Rules of Thumb, expressing yourself clearly becomes less complicated. There are only 9 reasons to use a comma. In all other cases it just isn’t needed. So let’s go over what those reasons are right now.
1. Person-Identifier + 2nd Person-Identifier
When you essentially identify a person twice you need commas before and after the 2nd Person-Identifier.
Mr. Schmidt, our Team Leader, will be at the meeting tomorrow.
Mr. Schmidt = Person-Identifier; our Team Leader = 2nd Person-Identifier.
I’d like to personally welcome you, Jane, as the new student in our class.
you = Person-Identifier; Jane = 2nd Person-Identifier.
Because the words, “our Team Leader” is a way to redefine Mr. Schmidt, commas are needed. If you took out Mr. Schmidt or our Team Leader, the sentence would still make sense.
The same is true in the second example, where I am addressing Jane directly. The person you is also Jane, so this is a way to define her in the context of my sentence. If you took out you or Jane, the sentence would still make sense.
Example of when you do not need commas in a sort-of-similar situation that sometimes confuses us:
Mr. Schmidt himself will be leading the meeting with our National Anthem.
No commas are needed before and after the word himself because that doesn’t define him; it just emphasizes that he’ll be doing something - and not someone else. If I were to take away the person-identifier Mr. Schmidt, the rest of the sentence would no longer make sense. It would read, “Himself will be leading…” and that has no meaning. Therefore, commas are not needed.
1.B. Identifier + 2nd Identifier (not a proper pronoun)
QUICKIE NOTE: We can also do this with things, to essentially identify a thing or a concept twice. For example, “They’re considered similar, or belonging to each other, because of the common way we use these words.” When you state something and then add an, “or this thing” type of phrase, that’s restating or redefining. So commas are needed.
You need a comma to clearly write a date.
We’re relocating our offices on May 21, 2017.
I was born on January 12, 1801.
3. Listing of Nouns
When listing nouns in a sentence you should separate those things with commas.
Don’t forget to bring pens, paper, a calculator, and plenty of water.
We’re going to need chocolates, Gummy Bears and apples for Halloween.
Important Note: If your list of nouns has more than 3 things in the list, then there must be a comma before the word and. If there are 3 or fewer than that, that last comma isn’t needed.
When you write a bit of dialogue you need a comma to start that.
Ms. Patterson said, “I don’t care when he says he needs the report. I need it now.”
My Great-Grandma always used to say, “No amount of learning is ever wasted.”
5. Letters & Emails
In a letter or email, we need commas after the greeting and the closing.
6. Lists of Adjectives (that aren’t too similar)
When listing adjectives to describe something you need commas - unless those adjectives are very similar.
Examples where commas are needed for adjectives:
We need this to be a clear, simple, informative presentation.
Their wedding was a lovely, memorable ceremony.
Examples where commas are NOT needed for adjectives:
You’ll find a quaint little hotel near the castle ruins.
His boss is just a crazy old fart.
Quaint and little are both adjectives, but we don’t need commas here because we think of these words as belonging to each other. Same thing goes for the adjectives crazy and old. Not that these adjectives are the same, but they’re considered similar, or belonging to each other, because of the common way we use these words.
7. Contrasting thoughts
We use commas to set off a contrasted thought, be that expressed in a word, phrase or clause.
Your coworkers might cooperate with you if you ask, not tell.
She’s tough and unrelenting, yet has a good heart.
We need commas after transitional words or expressions to indicate a pause or emphasis on something.
Therefore, we need to tackle this problem head-on.
Indeed, I had a wonderful time.
In this case, the decision wasn’t a surprise.
Yes, I like him very much.
Well, I really don’t know what he thinks about that.
Important Note: You will NOT need commas if you push or pull the transitional word or phrase out of the beginning of the sentence.
We need to therefore tackle this problem head-on.
I had indeed a wonderful time.
The decision in this case wasn’t a surprise.
9. Too long sentences!
If you have two parts of a sentence that could be divided into two sentences, you either need a comma or you need to split them into two sentences.
He has been panting over her for such a long time, it’s ridiculous that he hasn’t asked her out yet.
She has no idea who he is because he’s so shy, but I bet she would be interested if he would just talk to her.
I’ve made a comma error somewhere in this tutorial. Can you find it?
If you have a spelling or grammar question that you just can’t wrap your head around, just send me an email - or leave a comment here. Chances are good that you’re not the only one!