First, an announcement. For the next couple of days, BIG IN JAPAN will be on SALE on Amazon and Kindle – $2.99 for the e-book version. That’s $26 off the hardcover list price. Bargain for your beach read, and it IS a great beach read, if I do say so myself. Here’s the link for Amazon, and the link for Barnes and Noble. Enjoy!

And now, it’s time for a little grammar, folks.

I do a lot of reading of manuscripts and papers for people, and there’s one comma error that crops up quite a bit–one that’s really easy to spot and super easy to avoid if you know a simple rule.

I call it a comma math.

I know, writers and math brained people, ne’er the twain shall meet. But forget that–this is so simple you won’t care about what your scores were on your 9th grade algebra tests.

First: S means subject. Like the subject of the sentence, and V means verb. The action. Conjunction is the and/but/or connector. (They’ll get you pretty far, Conjunction Junction, what’s your function?)

S+V comma conjunction S+V

SV (no comma) conjunction V

That’s it.

Simply, if you have a subject and verb (a.k.a., complete simple sentence) on one side of the conjuction, AND a complete simple sentence (S+V) on the other, then USE A COMMA.

If you don’t have both on both sides, LEAVE OFF THE COMMA.

Examples:

Mary ran, and Joe threw the ball.

Mary ran and threw the ball.

In the first sentence there are two subjects and two verbs. In the second, there’s only Mary doing both verbs. So COMMA in the first one, NO COMMA in the second. It doesn’t matter how much more complex the sentence gets with prepositional phrases or adjectives, etc., this is a great gauge for whether you need a comma in the sentence.

Happy comma-use, friends. I hope that was clear. Leave a comment if you have a question — or a better way of stating this principle. I’m all ears!