Apostrophe rules

An apostrophe does exactly two jobs: it shows possession (Maya's phone) and it marks missing letters in a contraction (don't). It never makes an ordinary plural.

See it work

Try:

the boss’s book

Singular noun ending in s: still add ’s (Chicago style and most common nouns).

Singular possessive: add 's

the dog's bowl, the boss's office, James's car. Chicago style adds 's even to names ending in s; AP style adds only an apostrophe to proper names ending in s (James' car).

Plural possessive ending in s: add only '

the dogs' bowls, the Smiths' house. Make the plural first, then add the apostrophe.

Irregular plurals: add 's

children's books, women's team, people's choice.

Never for plurals

Apple's £1 and the 1990's are errors: write apples and the 1990s. The one widely accepted exception is single lower-case letters: mind your p's and q's.

Possessive pronouns take none

its, yours, hers, ours, theirs, whose. With an apostrophe, it's and who's are contractions.

Joint and separate ownership

Sam and Lee's flat (they share one). Sam's and Lee's flats (each has their own).

Frequently asked

Is it "James'" or "James's"?

Both are accepted. Chicago style prefers James's; AP prefers James'. Be consistent.

Where does the apostrophe go in "the Joneses"?

Plural family name: the Joneses. Possessive of that plural: the Joneses' car.