Those Pesky Little Commas!

Having troubles with comma usage? Well, you're not alone. I wrote this column to remind myself of the most common uses for the little buggers, and hope that you benefit from what I have learned.

A while back, I promised to do a topic on commas. It has taken me a while to find the right way to explain everything (and understand it) so I'm going to take a stab at this, and I hope I don't mess it up.

What follows are the 'most common' comma rules but by no means all of them. I will give examples where I can and hopefully we will all learn from this, okay?


The most common comma usage, is to help make sense out of a sentence that could easily be misread.

As an example:

When you are eating cats better stay off the table.

Now, if you read the whole sentence you could figure it out, but your first instinct is ‘When you are eating cats’ and you don’t even *want* to finish the sentence. A comma helps fix this, as so:

When you are eating, cats better stay off the table.


Another usage is to join two independent clauses. Independent clause? What’s that? It’s a sentence, like, ‘John went to the store.’

So, let’s say you have this: John went to the store. John bought milk. Seems like we could combine these, right? Yep, do it as so:

John went to the store, and he bought milk.

A coordinating conjunction (and, but, or, etc,) must be used and the comma must be placed before the coordinating conjunction.

So, is this okay?

John went to the store, and bought milk.

Nope. ‘John went to the store.’ is a complete sentence – ‘bought milk.’ Is not. Rewrite this as follows:

John went to the store and bought milk.

Now, if the two independent clauses are short you can omit the comma, but it’s far better to learn the rule and abide by it – there is no crime in using the comma when the clauses are short.

Also, you can’t do this:

John went to the store, he bought milk.

It sounds bad without the conjunction, and it creates a comma splice – bad, very bad.


You also use a comma after an introductory clause. So, what is an introductory clause? It’s a sentence fragment. You still need a full sentence after the clause, and in this case you omit the coordinating conjunction.

As an example:

After John arrived at the store, he bought milk.

‘After John arrived at the store’ is the introductory clause, and ‘He bought milk.’ is the complete sentence.


You also use a comma after an introductory phrase, like so:

Under the bridge, an old hobo was eating his shoe.

The difference between this example and the one before it is the beginning of the sentence is a phrase (a group of words without a subject and a predicate).

Phrase or clause, you use the comma.


Another use for a comma is to offset interruptions. Example:

Thus, that’s why we ran to the bank.

Another example:

The bank, unfortunately, was far away.

In the first sentence, you could remove the word ‘thus’ and have the same meaning. In the second sentence, the word ‘unfortunately’ is treated the same way. Thus, you set them off with commas.


You also use commas to offset restrictive elements in a sentence.

Example:

The bank teller, who lives down the street, waited on us.

This is non-restrictive and needs a comma as ‘who lives down the street’ is just unneeded info

However:

The bank teller with the red hat waited on us.

No commas, as we are now talking about a *specific* teller – the one in the red hat.


There are many other comma rules, but these will work you past a good 90% of the difficult ones.

Now, according to the rules I listed, did I place any commas where they didn’t belong? Did I omit any?

It wouldn’t be much of a lesson if I didn’t give you a chance to apply your knowledge. Feel free to proofread what I have written, and fear no retribution, as I made a few mistakes (outside of the examples, which are all correct) in the hopes that you could learn from some practice.