their

American  

[thair, ther] / ðɛər, ðər /

pronoun

1. a form of the possessive case of plural they used as an attributive adjective, before a noun.

   their home;

   their rights as citizens;

   their departure for Rome.

2. a form of the possessive case of singular they used as an attributive adjective, before a noun.

   1. (used to refer to a generic or unspecified person previously mentioned, about to be mentioned, or present in the immediate context): A parent should read to their child.

      Someone left their book on the table.

      A parent should read to their child.

   2. (used to refer to a specific or known person previously mentioned, about to be mentioned, or present in the immediate context).

      I’m glad my teacher last year had high expectations for their students.

   3. (used to refer to a nonbinary or gender-nonconforming person previously mentioned, about to be mentioned, or present in the immediate context).

      My cousin Sam is bad at math, but their other grades are good.

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their British  

/ ðɛə /

determiner

1. of, belonging to, or associated in some way with them

   their finest hour

   their own clothes

   she tried to combat their mocking her

2. belonging to or associated in some way with people in general not including the speaker or people addressed

   in many countries they wash their clothes in the river

3. belonging to or associated in some way with an indefinite antecedent such as one, whoever, or anybody

   everyone should bring their own lunch

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Grammar

See he ¹, me, they.

Usage

What’s the difference between their, there, and they're? Their is the possessive form of the personal pronoun they, essentially meaning belonging to or possessed by them, as in Is that their car, or ours? There is commonly used to introduce sentences or to indicate where something is, as in It’s over there, next to the window. They're is a contraction of they are.There are many instances in which they’re confused because their pronunciations are exactly the same. (See what we did there?)There are easy ways to remember which spelling is right, and they’re actually built into each word.You can remember that their is the one that’s used to show possession (like his and her) by remembering that it includes the word heir (a person who inherits possessions).When it’s used to indicate location, there functions a lot like here (even though it can mean the opposite), and the word here is right inside of it.The apostrophe in they’re indicates that it’s a combination of two words and signals that it’s the one you want to use when you mean they are.Here’s an example of their, there, and they're used correctly in the same sentence.Example: It’s hard to work as a team in that environment—when they’re in there, they’re their own worst enemies.Want to learn more? Read the full breakdown of the difference between their, there, and they're.

Etymology

Origin of their

First recorded in 1150–1200; Middle English their(e), ther(e), from Old Norse theirra “their”; replacing Old English thāra, thǣra; they

Example Sentences

Dogs and cats' senses are different to humans', so the channel's colours, refresh rates and audio frequencies have been designed to suit their specific needs, it said.

From Barron's • Apr. 3, 2026

In an era where the best prospects stop by college for just a single season on their way to the NBA—and collect millions of dollars in NIL payments—Hurley’s all-out approach hasn’t attracted the biggest names.

From The Wall Street Journal • Apr. 3, 2026

The crew were accompanied by a plushie of their Moon mascot, designed by eight-year-old Lucas Yee from San Francisco, as they broadcast live from space.

From BBC • Apr. 3, 2026

Clips of a duckling swimming in a bath or two happy pooches patrolling their neighbourhood are examples of the curated programming on "PetTV".

From Barron's • Apr. 3, 2026

At five, we carried lunch boxes filled with our Polly Pocket figurines, their tiny rubber outfits, and their shoes no bigger than a Tic Tac mint.

From "Legendary Frybread Drive-In" by Cynthia Leitich Smith