Grammar Goody : When to use commas

You're stumped on how and when to use commas, right? That's because if you were taught it at all, no one  held your feet to the fire and actually made you do it. So, gradually you forgot.

Fortunately for you, commas are among the easiest of punctuation marks to learn the proper placement of.

This last sentence reminds me of an old story about Winston Churchill, the great British prime minister during World War II. He was once scolded for ending a sentence with a preposition (as I just did above when I wrote the "proper placement of"). Churchill had had enough of such pedantry, and he replied saying something like "that is a criticism up with which I will not put....)

But I digress. Back to commas. We'll start with rule #1 today and continue with others in succeeding days (I know, I know, you just can't wait, but you'll have to be patient...)

1. Put a comma before and if the and is connecting two independent clauses, as in this:


She decided to go to the wedding, and she knew exactly what she would wear. 


So, what's an independent clause? It is a part of a sentence that can stand on its own as an independent sentence. In our example above, we have two independent clauses.

(1) She decided to go to the wedding (could stand as a complete sentence on its own)
AND
(2) she knew exactly what she would wear (also could stand as a complete sentence on its own).


Now, that comma may seem unnecessary, but it it's not. It's required in good writing. 


This rule is also cool with or, but, or nor--not just and. 


Going back to my lame example sentence above, the comma placement would be the same if we substituted but for the and. 


She decided to go to the wedding, but she had no idea what to wear.