The Comma Clause

Questions about commas outnumber all other Grammar Cop questions. Why is the comma so confusing? For one thing, usage and preferences vary. One editor may prefer all but the simplest clauses be offset by commas while another may be a comma minimalist. Author Steve Berry once told me he’s the self-proclaimed comma-kasee. He rarely uses a comma and sells a lot more books than I, so who am I to judge? 

Here are a few basic rules to help you. Keep in mind, however, no matter what you read or hear, your publisher has the final authority. Only debate a comma placement when it is a matter of changing the sentence’s meaning. Before you debate with an editor, be sure you have a clear understanding of clauses and sentence structure.

Comma Rules in a Nutshell:

An independent clause (Subject + Verb) doesn’t need a comma. A dependent clause does. 

Consider this paragraph:

My backpack weighs a ton. The straps, which bear the weight of six textbooks and a laptop, must be reinforced. I wouldn’t wear a backpack but need my hands free for the handlebars of my bicycle. No matter how often I organize and repack the books, I have no space available for my iPod.

The first sentence is easy. It’s a simple, independent clause. The second sentence is a compound sentence because we add the dependent clause modifying the subject straps. The dependent clause, so named because it’s not a complete sentence on its own, should be set aside with a pair of commas (think of them as parentheses). If you delete the dependent clause, the sentence still stands: The straps must be reinforced is an independent clause.

Unless a dependent clause is used as an introductory clause, it should be offset by a pair of commas, one at the beginning and one at the end of the clause. The straps, which bear the weight of six textbooks and a laptop, must be reinforced. Commas aren’t necessary in I wouldn’t wear a backpack but need my hands free for the handlebars of my bicycle. “I” is the subject of both wouldn’t wear a backpack and need my hands free. If written as two independent clauses, it would need a comma before the conjunction but I wouldn’t wear a backpack, but I need my hands free for the handlebars of my bicycle.

Commas have other uses, too, i.e. separating items in a series: Inside my backpack are pencils, a calculator, textbooks, and a laptop. 

A rule of thumb is write the sentence first without commas. If it makes sense without a pause, leave it alone. If you find the sentence convoluted and confusing, you need a set of commas.

Calm the Comma-phobia

The most questions I get from my readers concern the comma. The comma intimidates writers (except author Steve Berry, the self-proclaimed Comma Kamikaze ☺). Unfortunately, correct comma usage is difficult to nail. The best I can offer comes from current acceptable standards found in updated reference materials.

In a sentence with two or more independent clauses, the comma must precede the coordinate conjunction (words such as and, but, for, so, yet, while, or, nor, and whereas).

She bought a new dress, and her sister bought a CD.

I do my reading and paper work in bed at night, while my brother stays up late watching Leno. 

No comma is used before and, but, or, nor, and yet when the coordinate conjunction joins two words, two phrases, or two dependent clauses.

He has neither the willingness nor the ability to pay his bill.

Bravely, she stepped onto the stage but realized she couldnt speak a word.

Why no comma in these two examples?  The clauses share a single subject. He hasn’t the willingness to pay. He hasn’t the ability to pay. She stepped on stage. She realized she couldn’t speak. In either example, we see two actions tied to a single subject.

What happens when a second subject is introduced?  We no longer have two dependent clauses:

You can make an appointment now, or we will call you later.

You is the subject of the first clause, and we is the subject of the second, bringing us back to the first scenario with two independent clauses.

Related to this is the couplet following a verb. In a simple sentence, the word and is sufficient.

They agreed to divide the cash and to put the stock in a trust fund.

Focusing on sentence structure is a good start to overcoming your comma-phobia. I’ve barely scratched the surface of the comma, so watch for future posts.