Behold the comma: it’s the most dreaded of punctuation marks, and one of the most misused and abused.
And for good reason. In the English language, most punctuation marks have no more than two or three uses. A period will always either end a sentence or abbreviate a word. An exclamation point indicates excitement.
Commas, on the other hand, are the Hufflepuff of grammar. They do some of everything.
They divide points in a list, they separate phrases in a sentence, they offset names and dates and states, they act as periods within interrupted dialogue.
In fact, it seems the one thing they don’t do is create an arbitrary pause. For example:
“My name, is Doctor Incredible!” just looks tacky. If you’re trying to pause for dramatic effect, you’re looking for an ellipse. It should really look like this: “My name… is Doctor Incredible!”
I started this post intending to write out all of the rules for properly placing a comma, but 1) I’d be here all day, and 2) the people below have said the same far more eloquently than I.
Purdue University’s Writing Lab site lists fifteen distinct rules for working with this slippery punctuation. Wikipedia has thirteen subsections on correct usage. Grammarbook.com has twenty-one. And even then, there’s more ways to make mistakes: The Opinion Page of the New York Times has a nice discussion of some common comma mistakes, as well as a Fanfare for the Comma Man— which discusses my next point:
The rules can change depending on who you ask. People will argue over these forever, so rather than giving you the rules, here’s some spots where you can throw them out and go with your gut.
- The infamous Oxford comma (the comma that precedes ‘and’ in a list), as in “bacon, milk, and cheese”)
- Modifying phrases at the beginning of a sentence, such as “Last night Boxy and I saw a movie”
If the use/omission of the comma doesn’t change the meaning of the sentence, then it can go either way. However, in some cases the comma can lead to confusion. Remember: clarity trumps all else.