If you are wondering whether the correct spelling is “theirs” or “their’s,” the answer is simple: theirs is correct, while their’s is incorrect in standard English.
The word theirs is a possessive pronoun. It is used when you want to show that something belongs to two or more people, or to someone referred to with singular “they.”
For example:
- This house is theirs.
- The blue car is theirs.
- I think this jacket is theirs.
You should not add an apostrophe to the word. Therefore, “their’s” is not the correct spelling.
The confusion is understandable because apostrophes are often used to show possession, such as in John’s car or the dog’s food. However, possessive pronouns follow a different pattern. Words such as hers, ours, yours, and theirs are written without apostrophes.
If you remember only one rule from this article, remember this:
The correct spelling is “theirs,” without an apostrophe.
Theirs or Their’s: The Quick Answer
The correct spelling is “theirs”
Theirs is the standard and correct form.
Example:
That house is theirs.
Here, “theirs” tells us that the house belongs to them.
“Their’s” is incorrect
Their’s is generally a spelling and grammar error.
Incorrect:
That house is their’s.
Correct:
That house is theirs.
The apostrophe does not belong in theirs.
Quick comparison
| Form | Correct? | Example |
|---|---|---|
| theirs | Yes | The decision was theirs. |
| their’s | No | The decision was their’s. |
| their | Yes, but used differently | It is their decision. |
The important point is that their and theirs are both correct words, but they perform different grammatical jobs.
Why Is “Theirs” Correct?
“Theirs” is a possessive pronoun
Theirs is a possessive pronoun used to indicate ownership or association.
A possessive pronoun can stand on its own rather than being placed directly before a noun.
Consider these two sentences:
This is their house.
This house is theirs.
In the first sentence, their comes before the noun house. In the second sentence, theirs stands on its own and refers back to the house.
This distinction is one of the easiest ways to understand when to use their and when to use theirs.
Possessive pronouns do not need apostrophes
One reason people write their’s is that they associate apostrophes with possession.
That works in some situations:
- Sarah’s book
- James’s bicycle
- the teacher’s desk
But an apostrophe is not automatically required whenever something shows possession.
Possessive pronouns have their own forms:
- my → mine
- your → yours
- her → hers
- our → ours
- their → theirs
Notice that these forms do not use apostrophes.
Therefore:
theirs ✅
not:
their’s ❌
Why Is “Their’s” a Common Mistake?
The apostrophe makes the spelling look logical
The mistake usually comes from applying a familiar spelling pattern to the wrong type of word.
For example:
The girl’s phone
shows that the phone belongs to the girl.
It is therefore tempting to think:
their + ’s = their’s
But their is not changed into their’s to create the possessive pronoun.
Instead, the established possessive-pronoun form is simply:
theirs
This is similar to the way English uses hers rather than her’s and ours rather than our’s.
“It’s” can also cause confusion
Another source of confusion is the word it’s.
It’s is a contraction of it is or it has. It does not mean that something belongs to “it.”
For example:
It’s raining.
means:
It is raining.
By contrast, its is the possessive form:
The company changed its policy.
This demonstrates an important point: apostrophes in English do not always indicate possession. In contractions, they show that letters have been omitted.
Understanding this distinction can make words such as theirs easier to remember.
Their vs. Theirs: What Is the Difference?
Use “their” before a noun
Their is generally used before a noun to indicate possession or association.
Examples:
They parked their car outside.
The students finished their homework.
The children brought their toys.
In each example, their is connected directly to a noun:
- their car
- their homework
- their toys
Use “theirs” when the noun does not follow
Theirs is used when the noun is understood and does not need to be repeated.
Compare:
This is their car.
with:
This car is theirs.
Both sentences express ownership, but their grammatical structures are different.
Another example:
We chose our seats, and they chose theirs.
Here, theirs means something like their seats. The noun does not need to be repeated because the meaning is already clear.
A simple test
If you are unsure whether to use their or theirs, look at the word that follows it.
If a noun comes immediately afterward, their is usually the correct choice:
their house
their idea
their teacher
their project
If the possessive word stands alone, theirs is usually correct:
The house is theirs.
The idea was theirs.
The project is theirs.
This simple distinction can prevent many mistakes.
Examples of “Theirs” in a Sentence
Examples showing ownership
Here are several natural examples of theirs:
- That car is theirs.
- The house at the end of the street is theirs.
- The final decision was theirs.
- Those books are theirs.
- We brought our equipment, and they brought theirs.
- This table is ours, but the chairs are theirs.
- I think the red umbrella is theirs.
- The responsibility for the project was theirs.
- Our approach was different from theirs.
- They said the choice was theirs to make.
In every example, theirs indicates that something belongs to or is associated with them.
Examples with “their” and “theirs” together
Seeing the two words side by side can make the distinction even clearer.
They brought their car, but we brought ours.
They brought their car, and the car parked next to us is theirs.
I like their design better than theirs.
The last example may sound unusual because the meaning depends on context, but grammatically it demonstrates that their modifies a noun while theirs functions independently.
Common Mistakes With “Theirs”
Mistake 1: Writing “their’s”
Incorrect:
The house is their’s.
Correct:
The house is theirs.
The apostrophe should be removed.
Mistake 2: Using “their” by itself
Sometimes writers know that their is correct but use it where theirs is needed.
Incorrect:
That car is their.
Correct:
That car is theirs.
Why? Because their normally modifies a noun, while theirs can stand alone.
You could also rewrite the sentence:
That is their car.
Both That is their car and That car is theirs are correct.
Mistake 3: Confusing possession with contraction
An apostrophe can indicate a contraction, as in:
they’re = they are
But theirs is not a contraction.
Similarly:
their = possessive determiner
theirs = possessive pronoun
they’re = they are
Keeping these forms separate helps prevent spelling errors.
Theirs vs. There’s vs. They’re
“Theirs”
Theirs shows possession.
The blue bags are theirs.
“There’s”
There’s is a contraction of there is or, in some contexts, there has.
There’s a problem with the computer.
You can test it by replacing there’s with there is:
There is a problem with the computer.
The sentence still works.
“They’re”
They’re is a contraction of they are.
They’re waiting outside.
You can test it by replacing they’re with they are:
They are waiting outside.
The sentence still works.
“Their”
Their is a possessive determiner.
They left their bags at the office.
These four words can sound similar in speech, but they have different meanings and grammatical functions.
Is “Their’s” Ever Correct?
“Their’s” is not the standard spelling
In standard modern English, their’s should be treated as incorrect.
If you mean that something belongs to them, use:
theirs
For example:
The responsibility is theirs.
not:
The responsibility is their’s.
You may occasionally encounter their’s in informal writing, historical material, user-generated content, or as a typo, but that does not make it the standard spelling.
For schoolwork, professional writing, websites, business communication, and other forms of standard English, use theirs.
Can “Theirs” Refer to One Person?
Yes, “theirs” can be used with singular “they”
Theirs can refer to one person when they/them is being used as a singular pronoun.
For example:
Someone left their phone on the desk. I think this one is theirs.
Here, theirs refers to one person whose identity is not specified.
It can also be used when an individual uses they/them pronouns:
Alex said the blue notebook was theirs.
Therefore, theirs is not limited to situations involving multiple people.
How to Remember “Theirs” Without an Apostrophe
Use the possessive-pronoun pattern
A useful way to remember the spelling is to look at similar words:
mine
yours
his
hers
ours
theirs
None of these possessive pronouns needs an apostrophe.
You would not normally write:
her’s
or:
our’s
So you should not write:
their’s
The correct form is:
theirs
Use the “noun test”
Ask yourself whether a noun comes immediately after the possessive word.
Noun follows → their
their house
their car
their opinion
Noun does not follow → theirs
The house is theirs.
The car is theirs.
The opinion is theirs.
This is not a rule that covers every possible construction in English, but it is an excellent practical guide for everyday writing.
Why Getting “Theirs” Right Matters in Professional Writing
A single spelling mistake is unlikely to determine how a page performs in search results, but accurate language matters for the people reading your content.
If someone searches “theirs or their’s,” they are probably looking for a quick, trustworthy explanation. A page that gives a clear answer and teaches the underlying rule creates a better experience than a page that repeats the keyword without adding useful information.
Correct grammar can also influence how readers perceive a website. Educational, business, and professional content benefits from being clear, consistent, and carefully edited.
The goal should therefore be more than simply telling readers that theirs is correct. A useful explanation should also show:
- why their’s is wrong;
- when to use their;
- when to use theirs;
- how possessive pronouns work;
- and how to avoid similar mistakes.
That approach answers the immediate question while also helping the reader solve the problem independently in the future.
Frequently Asked Questions
Is “theirs” or “their’s” correct?
Theirs is correct. Their’s is an incorrect spelling in standard English.
Correct:
The house is theirs.
Incorrect:
The house is their’s.
Why is “their’s” incorrect?
Theirs is a possessive pronoun, and possessive pronouns such as hers, ours, yours, and theirs do not require an apostrophe.
The apostrophe in their’s is therefore unnecessary.
Is “their” also correct?
Yes. Their is a correct word, but it is used differently from theirs.
Use their before a noun:
This is their house.
Use theirs when the possessive word stands alone:
This house is theirs.
Can I write “their’s” in informal English?
You may encounter their’s in informal writing or online content, but it is still considered an incorrect standard spelling. If you want your writing to follow standard English conventions, use theirs.
Is “theirs” a possessive pronoun?
Yes. Theirs is a possessive pronoun. It indicates that something belongs to or is associated with them.
Example:
The final decision was theirs.
Can “theirs” be singular?
Yes. Theirs can be used with singular they.
Example:
Someone forgot their coat, and I think this one is theirs.
What is the difference between “their” and “theirs”?
Their normally comes before a noun:
their car
Theirs can stand alone:
The car is theirs.
Does “theirs” need an apostrophe?
No. The correct spelling is theirs, without an apostrophe.
Conclusion
When choosing between “theirs” and “their’s,” always choose theirs.
Theirs is the correct possessive pronoun, while their’s is an incorrect spelling in standard English. The confusion usually comes from the fact that apostrophes are commonly associated with possession, but possessive pronouns such as hers, ours, yours, and theirs do not use apostrophes.
I am Nathaniel Brooks, a writer passionate about education and lifelong learning. I believe good educational content should be easy to understand, useful, and enjoyable to read. At Teachlora, I create helpful articles about learning techniques, study habits, general knowledge, and skills that can support readers in their educational journey. I have also written Learn Better Every Day and The Practical Student Handbook to help readers approach learning with more confidence.
Books:
- Learn Better Every Day
- The Practical Student Handbook
Clara Kensington
Eleanor Whitmore