Booher's Rules of Business Grammar - Dianna Booher 2009

One car, two cars, three cars, four
Punctuation problems

COMMAS TO SEPARATE EQUAL THINGS

Have you ever sat at a railroad crossing and watched as car after car after car after car passes, with no end to the train in sight? Some people write and speak that way—an unending ramble, with no destination in sight.

Maybe you’ve heard an excited child tell a saga something like this: “I was outside playing and this big dog came up and started barking and we couldn’t see what he was barking at so we started following him because he was running back and forth toward the sidewalk and the swings and then we noticed his leg was hurt and Tony tried to pat him but he pulled away and started barking even louder and then this guy came up and said the dog belonged to him and he started yelling at us to stop bothering his dog but we weren’t doing anything to his dog except trying to see if his foot was hurt because it looked like it was bleeding.”

You want to tell the child, “Just take a breath. Relax.” This same sort of loosey-goosey writing sometimes creeps into engineering proposals, audit reports, and management e-mails. The writer drafts nine clauses without a comma or period to separate them.

Every time you write a complete thought (an independent clause—a group of words with a subject and a verb that stands alone), you have a choice of punctuation:

1. End with a period.

2. End with a semicolon followed by another closely related complete thought.

3. End with a comma and one of seven linking words, before joining another closely related complete thought.

If you select option 3, here are the seven linking words: and, but, so, or, for, nor, and yet. That’s it. Those seven and no more. Not a tough list. And, but, or so will be appropriate about 90 percent of the time. The other four words will share the spotlight the remaining 10 percent of the time.

When joining independent items with one of those seven linking words, separate them with commas.

Independent clauses joined by coordinate conjunctions (and, but, or, so, nor, for, yet)

Items in a series (“Brunhilda brought water, crackers, and gum on the plane.”)

Distinct adjectives when they equally describe the noun or pronoun (“Pudge was a cantankerous, belligerent man.”)

Memory tip

Back to the traffic metaphor: Picture yourself sitting in your car at the entrance ramp to a major tollway. You’ve tossed your money into the collection basket. The green light flashes, and the gate arm lifts to permit one car to enter the flow of traffic. The gate arm separates each car as it enters the tollway.

The comma serves the same function between the flow of equal, independent items in a series or sentence.