Apostrophe Rules: Possession and Contractions Explained

CorrectNow Editorial Team · 6 min read

The apostrophe has two main jobs in English: showing possession and marking missing letters in contractions. Most apostrophe errors happen when it is asked to do a third job it does not have, usually making a word plural.

Below are the rules that cover most situations, with examples of what to write and what to avoid, plus a few cases where style guides allow a choice.

Possession with singular nouns: add 's

To show that something belongs to one person or thing, add an apostrophe and s: the teacher's desk, the company's website, a week's notice.

For singular nouns and names ending in s, style guides differ. Many recommend adding 's, as in James's car or the boss's office. Others accept the apostrophe alone for names, as in James' car. Both appear in published writing, so pick one style and use it consistently.

Incorrect: The managers office is on the second floor. – Correct: The manager's office is on the second floor. (One manager, so add 's. If several managers share the office, write managers'.)

Possession with plural nouns

For plural nouns that already end in s, add only an apostrophe after the s: the students' results, the two companies' agreement.

For plural nouns that do not end in s, add 's just as you would for a singular noun: children's books, women's football, people's choices.

Time expressions follow the same pattern: one day's work, two weeks' notice.

Incorrect: The childrens' toys were everywhere. – Correct: The children's toys were everywhere. (Children is already plural and does not end in s, so add 's.)
Incorrect: The girls's hostel is near the library. – Correct: The girls' hostel is near the library. (Girls is a plural ending in s, so add only the apostrophe.)

Contractions: the apostrophe marks missing letters

In a contraction, the apostrophe sits where letters have been left out: do not becomes don't, I am becomes I'm, they have becomes they've, and it is becomes it's.

Put the apostrophe where the letters are missing, not where the two words join. The same idea applies to shortened years, as in the class of '98, where the apostrophe replaces the first two digits.

Incorrect: Do'nt forget the meeting. – Correct: Don't forget the meeting. (The missing letter is the o in not.)
Incorrect: She does'nt agree. – Correct: She doesn't agree. (Doesn't is does not with the o removed.)
Incorrect: Were ready to start. – Correct: We're ready to start. (Without the apostrophe, were is a past form of be, not we are.)

Plurals do not need apostrophes

An apostrophe does not make a noun plural. This applies to ordinary words, family names, abbreviations and decades.

One widely accepted exception is single lowercase letters, where an apostrophe prevents confusion, as in mind your p's and q's.

Incorrect: We sell new and used car's. – Correct: We sell new and used cars. (Cars is a simple plural.)
Incorrect: The Sharma's are coming to dinner. – Correct: The Sharmas are coming to dinner. (The family name is plural here, not possessive.)
Incorrect: She grew up in the 1990's. – Correct: She grew up in the 1990s. (Most style guides write decades without an apostrophe.)
Incorrect: The FAQ's are on the help page. – Correct: The FAQs are on the help page. (Abbreviations form the plural with s alone.)

Possessive pronouns, and who's vs whose

Possessive pronouns never take an apostrophe: yours, hers, ours, theirs, its and whose.

When you see it's, who's, you're or they're, the apostrophe signals a contraction, not possession. Who's means who is or who has, while whose shows ownership.

Incorrect: Who's phone is ringing? – Correct: Whose phone is ringing? (The question is about ownership, so use whose.)
Incorrect: The final decision is our's. – Correct: The final decision is ours. (Ours is a possessive pronoun and takes no apostrophe.)

Shared and separate ownership

When two people own something together, put the apostrophe on the last name only: Anita and Ravi's flat means one flat that they share. When each person owns something separately, add it to both names: Anita's and Ravi's phones means each has their own phone.

If the joint form starts to feel awkward, rewrite it: the flat that Anita and Ravi share.

Apostrophes are small, so they are easy to miss in a final read. The CorrectNow editor checks punctuation along with spelling and grammar, and each suggestion comes with a short explanation, which helps you decide whether a possessive or a plain plural is what you meant.

Frequently asked questions

Is it James' or James's?

Both are used. Many style guides prefer James's, while others accept James'. Choose one and stay consistent throughout the document.

Do you use an apostrophe to make a word plural?

No. Plurals take a plain s or es: cars, boxes, the Sharmas, the 1990s. Single lowercase letters, such as p's and q's, are a common exception.

Where does the apostrophe go in a plural possessive?

If the plural ends in s, put the apostrophe after the s: the students' results. If it does not, add 's: the children's books.

Is it its or it's for possession?

Its. It's always means it is or it has.

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