One easy way to rile a grammarian is to misuse your apostrophes.
The rules are pretty simple:
Is your word pural? (That is, are there more than one?) Then add only an s (or an es if the noun ends in an s, x or z)—no apostrophe is needed. This rule applies even for numbers and acronyms. These examples are all correct:
A thousand thank-yous
Four Billys in this class
The Williamses next door
All the Perezes at the reunion
Dos and don’ts
Is your word possessive? (That is, are you expressing ownership?) Then add an apostrophe with your s (or use just an apostrophe if the possessive is pronounced the same way as the root word):
My dog’s leash
My cats’ dishes (I have two cats!)
John Williams’ house
The Perezes’ family photos
Ramses’ reign in Egypt
NASA’s next mission
You need to remember one exception: Its, with no apostrophe, is possessive: My dog is chasing its tail. And it’s is the contraction for it is: It’s time for dinner.
Trust us. You don’t want to rile a grammarian. It makes us singularly tense.
By Jan Taylor, Editorial Project Manager with TalentMEDIA Services. You can reach her at firstname.lastname@example.org.