Column: A Word, Please: Proper grammar to ring in the holidays

Don’t touch that holiday greeting card. Don’t send out those event invitations. And whatever you do, don’t have a gift engraved, embossed or embroidered until you read this column.

It’s time, once again, for the “A Word, Please” holiday tradition: warning hosts, hostesses and gift-givers of the most common mistakes of the season: incorrectly formed plurals, possessives and plural possessives.

This year, let’s start with a quiz. See if you can spot the error in the following sentences. Then decide how you would correct it.

We’re having dinner at the Wilson’s house this year.

We had dinner at the Williams’s house last year.

James’ Christmas tree is really beautiful.

Happy holidays from the Chavez’s!

Here are the answers, along with explanations of how you can get them right next time.

“We’re having dinner at the Wilson’s house this year” should swap positions of the apostrophe and S: the Wilsons’ house. Most people get this wrong. But you already know how to get this right.

Just apply your basic understanding of how to form regular plurals and how to form possessives of regular plurals. To make a plural, add S: one shoe, two shoes, one pizza, two pizzas. To make a plural possessive, you put an apostrophe after the S: the cats’ tails, the houses’ roofs.

If you make Wilson plural, you get Wilsons. If you then make it possessive, you get the Wilsons’ house. Our original example would, however, be correct in the unlikely event you’re eating at the home of one guy who calls himself “The Wilson.” If that’s the case, don’t eat the giblets.

Our second sentence takes this lesson and throws in a curve ball. Unlike Wilson, Williams ends in S. That’s an extra layer of confusion. It’s no harder than the plurals and possessives you get right every day, just more confusing.

First, make the noun Williams into a plural: Williamses. Then add the possessive apostrophe according to the rules that gave us “the cats’ tails.” That gives us “We had dinner at the Williamses’ house last year.”

Confession time: The example “James’ Christmas tree is really beautiful” was a trick. It’s not an error. Neither is “James’s Christmas tree is really beautiful.” Singular proper nouns that end in S can be made possessive with either an apostrophe plus an S or just the apostrophe. There’s no one right way.

But if you want some help choosing, keep in mind that academic writing and book publishing like it when you add the extra S: James’s Christmas tree.

Finally, we arrive at the last example, “Happy holidays from the Chavez’s!” If you can’t suss this one out, don’t feel bad. Professional editors are pretty much the only people I know who can nail this.

But it’s easier than you think. Just keep this one little fact in mind: Words that end in Z work the same way as words that end in S. The same is true for Ch, Sh, X and other “sibiliants,” meaning sounds similar to that of the letter S.

So you take one Chavez, throw in a spouse Chavez and maybe a little Chavez or two, and you get Chavezes. You’re done.

That last question didn’t involve any possessives at all. If it had, it might have been about the Chavezes’ house or something. But it wasn’t possessive, so it’s just “Happy holidays from the Chavezes!”

But even names that don’t end in S or Z get their plural forms messed up a lot. So just remember that if your name is Smith or Johnson or Mooney or Casagrande or Medici, just add an S to make it plural and, if it’s also possessive, follow the S with an apostrophe.

“Happy holidays from the Medicis!”

“We’ll see you at the Smiths’ house.”

“We’re spending Christmas with the Casagrandes.”

“The Mooneys’ daughter will be in town this year.”

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