Ask the Editor: Commas

People seem to find commas confusing.  Most writers either get a little (or a lot) comma happy, or they are comma shy and don't use commas when they should.  So editors like me end up with manuscripts covered in commas (I call these comma pox ms--it's like they have a disease) or manuscripts with a billion run-on sentences.

Here a few tips for using commas correctly:

• If there are two clauses joined by a conjunction (and, but, or, etc.) and both of those clauses would make sense as stand alone sentences if the conjunction were removed, then place a comma before the conjunction.
• Example:  The dog went to the park, and he chased a ball. 
• If a sentence is offset by an introductory word/phrase, then use a comma.  
• Example: Therefore, the dog chased the ball at the park.
• Example: Running as fast as he could, the dog suddenly realized his master hadn't even thrown the ball!
• More explanation:  If you can cross out the first word/phrase and the sentence would still make sense, then you should probably use a comma.
• Use a comma to separate a list of three or more things.
• Example: The dog played with a ball, a Frisbee, and a squishy toy.
• Note:  Technically the Oxford comma is now considered optional.  Therefore, you could write this sentence as follows: The dog played with a ball, a Frisbee and a squishy toy.  I am a fan of the Oxford comma.  I will almost always add it in if the writer chose to eliminate it.
• Use a comma to set of a parenthetical phrase (extra information).
• Example:  Lauren, his six year old daughter, jumped rope in the front yard.;
• Use a comma to set off quotations (someone speaking, for example).
• Example: "Come here boy," the man said to his dog.