Apostrophes are frequently misused, but the rules about them aren’t complicated.
If you have a singular noun that doesn’t end in -s, add an apostrophe + s.
The dog’s dinner smells strange.
Marie’s bouquet includes orchids.
If you have a singular noun that ends in in -s, you can either add an apostrophe + s, or just add an apostrophe.
Chris’s treasure chest is hidden on this island.
Chris’ treasure chest is hidden on this island.
If you have a plural noun that doesn’t end in -s, add an apostrophe + s
After much questioning, we discovered the children’s mischief.
The mice’s squeaks terrified me.
If you have a plural noun that ends in -s, only add an apostrophe after the -s.
On Saturdays, I go to the farmers’ market.
The musicians’ performances have all been fabulous.
When letters are left out of a word or digits are left out of a number, that omission is indicated by an apostrophe. Here are some common contractions:
Could’ve (Could have)
Don’t (Do not)
We’re (We are)
The commonly confused contractions it’s, they’re, and you’re are covered in this lesson.
Before you go any farther, I want to make something clear: using apostrophes to pluralize is the exception, not the rule. The only times you can use an apostrophe when pluralizing are with letters and numbers (and even in these cases, you don’t have to use an apostrophe).
If it’s not a letter or number, just add -s. All of the following examples are correct:
You didn’t cross your t’s.
You didn’t cross your “t”s.
My sister-in-law has two PhD’s.
My sister-in-law has two PhDs.
Natalie is the only person I know who loves 80’s fashion.
Natalie is the only person I know who loves ‘80s fashion.