Guidelines for Using Apostrophes Correctly

1. Use an Apostrophe to Show the Omission of Letters in a Contraction

Use the apostrophe to form contractions:

• I'm (I am)
• you're (you are)
• he's (he is)
• she's (she is)
• it's* (it is)
• we're (we are)
• they're (they are)
• isn't (is not)
• aren't (are not)
• can't (cannot)
• don't (do not)
• who's (who is)
• won't (will not)

* Don't confuse the contraction it's (meaning, "it is") with the possessive pronoun its:

• It's the first day of spring.
• Our bird has escaped from its cage.

2. Use an Apostrophe with -s for Possessives of Singular Nouns

Use an apostrophe plus -s to show the possessive form of a singular noun, even if that singular noun already ends in -s:

• Harold's crayon
• my daughter's First Communion
• Sylvia Plath's poetry
• Dylan Thomas's poetry
• today's weather report
• the boss's problem
• Star Jones's talk show
• Victoria Beckham's husband

3. Use an Apostrophe Without -s for Possessives of Most Plural Nouns

To form the possessive of a plural noun that already ends in -s, add an apostrophe:

• the girls' swing set (the swing set belonging to the girls)
• the students' projects (the projects belonging to the students)
• the Johnsons' house (the house belonging to the Johnsons)

• the women's conference (the conference belonging to the women)
• the children's toys (the toys belonging to the children)
• the men's training camp (the training camp belonging to the men)

4. Use an Apostrophe with -s When Two or More Nouns Possess the Same Thing

When two or more nouns possess the same thing, add an apostrophe plus -s to the last noun listed:

• Ben and Jerry's Cherry Garcia Ice Cream
• Emma and Nicole's school project (Emma and Nicole worked together on the same project)

• Tim's and Marty's ice cream (Each boy has his own ice cream.)
• Emma's and Nicole's school projects (Each girl has her own project.)

5. Do Not Use an Apostrophe with Possessive Pronouns

Because possessive pronouns already show ownership, it's* not necessary to add an apostrophe:

• yours
• his
• hers
• its*
• ours
• theirs

• anybody's guess
• one's personal responsibility
• somebody's wallet

• It's the first day of spring.
• Our bird has escaped from its cage.

6. Generally, Do Not Use an Apostrophe to Form a Plural

As a general rule, use only an -s (or an -es) without an apostrophe to form the plurals of nouns--including dates, acronyms, and family names:

• Markets were booming in the 1990s.
• The tax advantages offered by IRAs make them attractive investments.
• The Johnsons have sold all of their CDs.

• Mind your p's and q's.
• Let's accept the proposal without any if's, and's, or but's.

RELATED BLOG POST: The Long Campaign to Abolish the Apostrophe