A Word, Please: Comma rules that may give you pause

A few weeks ago, I mentioned in this space that serial commas, also called Oxford commas, are a matter of style. So either “red, white and blue” or “red, white, and blue” can be correct depending on whether you’re following, say, Associated Press or Chicago style.

If you’re not bound by either one, you can choose whichever way you prefer.

But not all uses of the comma are as forgiving. So here are a few pointers for using commas perfectly.

Compare these two sentences: He wore a bright red cowboy hat. He wore a loud, ugly, ridiculous hat.

Do both appear to be punctuated correctly? They are. So how do we explain that the second one has commas between its adjectives while the first one does not? It has to do with “coordinate adjectives” and “noncoordinate adjectives.”

Coordinate adjectives function as though they have a coordinating conjunction -— namely, “and” — between them. Noncoordinate adjectives, on the other hand, have different relationships with the noun.

Insert some “ands” in our examples and you’ll see what I mean: “He wore a bright and red and cowboy hat.” That doesn’t work because “cowboy” is much more closely associated with “hat” than “bright” is. In fact “bright” seems to have more to do with the adjective “red” than it does with “hat.”

Now try changing the order of the adjectives: a cowboy red bright hat. Nonsense, right? That’s another way you know that these are not coordinate adjectives and, therefore, don’t take commas between them. But as a simple guide, remember that if the word “and” works well between adjectives, you can put commas there instead.

Here’s another misunderstood job of the comma: When you use a comma before “Inc.,” a state or a year, you need one after too. To see why, read this sentence aloud with an exaggerated pause at every comma: On Jan. 31, 2008 he started working for Consolidated Systems, Inc. in Fresno, Calif. at the company’s headquarters.

Hear the problem? Without a comma after 2008, Inc. and California, these words are associated more strongly with the stuff that follows them, as if 2008 begins a whole new thought. That’s an error. Commas set off parenthetical information, similar to the way parentheses do. So for this task, commas work in pairs.

Now look at this sentence and see if you can pinpoint something the writer is accidentally revealing: The guest list will include my husband Ted and my sister, Jennifer.

If you understand commas, you now know two things about the writer: She has just one sister and she’s a polygamist. That’s because commas set off nonrestrictive information — supplemental information that does not add specificity to a noun — while the absence of commas can indicate the opposite: that the information is crucial to knowing which sister, husband or other thing you’re talking about.

So when I talk about my sister, Jennifer, the comma tells you that the words “my sister” are in no way made more specific by the name Jennifer. Conversely, if I mention my sister Jennifer, the absence of a comma before the name tells you I have more than one sister. Similarly, if I mention “my husband Ted” without a comma, it means the name is needed to make clear which husband I’m talking about.

Finally, a little-known fact about the comma is illustrated in the following two sentences: Lance likes butter but hates margarine. Lance likes butter, but he hates margarine.

Why does the second one have a comma while the first one doesn’t? Because the second sentence has two whole clauses, each complete with subject and verb. The first sentence has two verbs, but the second one doesn’t have a subject. The rules say a comma goes between complete clauses joined by a conjunction like “but.”

JUNE CASAGRANDE is the author of “The Best Punctuation Book, Period.” She can be reached at JuneTCN@aol.com.