Apostrophe — Meaning, Rules, and Examples
What is an apostrophe?
An apostrophe (') is a punctuation mark that indicates the possessive case, omission of letters (contractions), and the pluralization of letters, abbreviations, and numbers. The placement of an apostrophe is dependent upon its function.
Apostrophe rules
The following rules apply to apostrophe use:
Rule 1: Singular Possession
To show that a noun possesses something, add an apostrophe -s to the end of the word.
Charlie's book is on the table.
If a singular noun ends in -s, then either add an apostrophe or an apostrophe -s to the end of the word.
Stephanie met her boss's wife at the luncheon.
Rule 2: Plural Possession
Place an apostrophe after the -s of a plural noun to show possession. It is not necessary to add -s after the apostrophe in a plural possessive noun.
The two actors' roles led both to Oscar nominations.
If a plural form does not end in an -s, add an apostrophe -s to make the possessive form.
The children's toys were scattered across the room.
Rule 3: Multiple Possession
Joint Ownership: If two or more people possess the same item, add an apostrophe -s to the last person identified.
Susan and Carl's house sold in record time.
Separate Ownership: If each person owns an individual version of the same item, both names should include an apostrophe -s.
Both Tim's and Rebeca's cars were a bright blue.
Rule 4: Contractions
Apostrophes allow for the creation of contractions, which is the shortening of two words by removing one or more letters. The apostrophe should replace the missing letter(s). The following are common contractions:
| Be | Will | Would | Have | Had | |
|---|---|---|---|---|---|
| I | I'm (am) | I'll | I'd | I've (have) | I'd |
| You | You're (are) | You'll | You'd | You've (have) | You'd |
| He | He's (is) | He'll | He'd | He's (has) | He'd |
| She | She's (is) | She'll | She'd | She's (has) | She'd |
| It | It's (is) | It'll | It'd | It's (has) | It'd |
| We | We're (are) | We'll | We'd | We've (have) | We'd |
| They | They're (are) | They'll | They'd | They've (have) | They'd |
| That | That's (is) | That'll | That'd | That's (has) | That'd |
Rule 5: Time or Money
When used as possessive adjectives, amounts of time and money require apostrophes.
Tyler wanted to add his two cents' worth.
Zachary took a three days' leave at the end of the summer.
Rule 6: Single Letters, Abbreviations, and Numbers
Individual lowercase letters that are plural should contain an apostrophe before the -s.
Make sure to cross your t's and dot your i's.
Many editors prefer writers use an apostrophe after a single capital letter.
Tina was elated that she received straight A's.
Use an apostrophe when omitting numbers within a year.
The '60s were far different from the '90s.
With groups of two or more capital letters, an apostrophe is unnecessary.
Not many people buy CDs anymore.
Rule 7: Holidays
There is no consistent rule identifying which holidays should contain an apostrophe. To determine if a holiday needs an apostrophe, check its official spelling.
April Fool's Day is before Mother's Day but after Veterans Day.
Rule 8: Personal Pronouns
The personal pronouns hers, ours, yours, theirs, its, whose, and oneself do not use an apostrophe to indicate possession.
Incorrect: Who's book is this?
Correct: Whose book is this?
Rule 9: False Possessives
Do not include an apostrophe with noun-derived adjectives that end in -s.
Incorrect: The couple picked several Beatles' songs for the reception.
Correct: The couple picked several Beatles songs for the reception.
Rule 10: Plural Nouns
Plural nouns should not contain an apostrophe unless it shows possession.
Incorrect: Several workers' called off sick today.
Correct: Several workers called off sick today.
When to use an apostrophe
Apostrophes should be used for the following:
Contractions
Possessive nouns
Joint possession
Years with omitted numbers
Certain holidays
Single lowercase and uppercase letters
Apostrophes should not be used with the following:
Plural words or numbers
Possessive personal pronouns
Noun-derived adjective
Apostrophe examples
Singular Possession
John's dog ran toward the mailman.
Why was Sara's brother not at the game?
I'm pretty sure that's Jess's coat on the floor.
Plural Possession
The trees' roots were not as deep as expected.
The water ruined all of the books' pages.
The men's dressing rooms are in the back of the store.
Joint Possession
Carol and Todd's restaurant opens in three weeks.
When will Paul and Beverly's kids arrive?
Lexie and Stan's car is in the shop.
Separate Possession
Laura's and Nick's essays were oddly similar.
Both Troy's and Lincoln's cars were red.
Olivia's, Hank's, and Piper's bikes were all new.
Contractions
We didn't know what time we'd arrive at the party.
Polly wasn't sure if she'd make it to the store after work.
I'm sure he'll agree to the terms of the contract.
Time and Money
Her house is about a one mile's drive from here.
They picked about ten dollars' worth of strawberries.
We took a two weeks' vacation before the start of the school year.
Letters, Abbreviations, and Numbers
Make sure your a's don't look like o's.
Out of 30 students, half received A's and B's.
What was it like growing up in the '70s?