Punctuation 101: The Comma

By Jill Williamson

Punctuation had never been my favorite thing. But I needed to learn the rules to look like a professional author. So do you! Trust me. One mistake here or there won’t get you rejected. But it your manuscript is filled with punctuation errors and misspellings, an agent or editor won’t keep reading.

I’ll try to explain this as simply as possible without boring you to death, but I highly recommend picking up a grammar book for your own reference. The Chicago Manual of Style is the reference for the publishing industry. Add a used copy to your wish list. It’s a great tool to have on your shelf.

I’m also not going to give you every comma rule. But here are a few that I see misused often.

Commas with Coordinating Conjunctions

There are seven coordinating conjunctions: and, but, for, nor, or, so, and yet. Basically, these are words that connect two clauses in a sentence. If you have a sentence that has one of those seven words in the middle, how do you now when you need a comma before the conjunction or not?

Simple. If the words on both sides of the conjunction are complete sentences by themselves, you need the comma to avoid having a run on sentence.

Ex: “Almost everyone on earth likes chocolate, but I can’t live without it.”

(You need the comma before ‘but’ because “Almost everyone on earth likes chocolate” is a complete sentence and so is “I can’t live without it.”)

If the sentence had one side that wasn’t a complete sentence on its own, a comma would be wrong. “Almost everyone on earth likes chocolate but my Aunt Sue who lives in Charlotte.” Since “My Aunt Sue who lives in Charlotte” is not a complete sentence, therefore a comma is not needed.

NOTE: For a very short sentence, you can omit the comma.

Ex: The bus departed and we were on our way.

Commas After an Introductory Word Group

When you start a sentence with an introductory word group, you need to separate it from the rest of the sentence with a comma.

Ex: When Martin was ready to eat, the waiter brought him a salad to start with.

NOTE: The comma can be omitted here in a very short sentence.

Ex: In no time we were in a different state.

Commas Between Items in a Series

When three or more items are listed in a series, those items should all be separated with commas. This applies to single words, phrases, or clauses. Note that a comma goes before the conjunction at the end of the sentence.

Ex: My favorite candy is M&M’s, Skittles, and Gummi Bears.

Ex: You can choose from going on a hike up the mountain, playing paintball in the field, going on a canoe ride, or swimming in the pool.

Commas Between Coordinating Adjectives vs. No Commas Between Cumulative Adjectives

Adjectives are coordinate if they can be joined with ‘and’ or if they can be scrambled and still make sense. Commas are required between coordinate adjectives.

Ex: Michael is a strong, tall, talented basketball player.

To test this example we first see if we can join the adjectives with ‘and’ and keep the same meaning.

Ex:  Michael is a strong and tall and talented basketball player.

Next we scramble the adjectives to see if this has an effect. Ex: Michael is a talented, strong, tall basketball player. Same meaning? Yep!

Cumulative adjectives lean on one another, with each modifying a larger word group. They do not require commas in between.

Ex: Four small white doves flew toward me.

When we test this sample joining the adjectives with ‘and’ is doesn’t work. Ex: Four and small and white and doves flew toward me.

When we scramble them, it also changes the meaning. Ex: “Small four white doves flew toward me.” This doesn’t work nor does, “White small four doves flew toward me.”

Thus ends this lesson on the comma. May you treat the little fellows well. And avoid mistakes like this:

How about you? What's the funniest comma mistake sentence you've seen?