Theirs or Their’s: Difference, Correct Usage, Apostrophe Rule, and Memory Tips Explained

Theirs is the correct spelling. Their’s is incorrect because possessive pronouns do not need apostrophes. Use theirs when something belongs to them and the noun is not repeated. The apostrophe may look tempting, but it does not belong in this word.

Quick Answer

Use theirs, not their’s.

• Correct: The blue car is theirs.
• Correct: This house is theirs.
• Correct: The final decision is theirs.

Their’s is always incorrect in standard English.

• Incorrect: The blue car is their’s.
• Incorrect: This house is their’s.
• Incorrect: The final decision is their’s.

The simple rule is: theirs already shows possession, so it does not need an apostrophe.

Theirs or Their’s: What Is the Difference?

The difference between theirs and their’s is simple: theirs is correct, and their’s is a misspelling. The word theirs is a possessive pronoun. It shows that something belongs to a group of people or to someone referred to as they.

Word	Status	Example
Theirs	Correct possessive pronoun	The choice is theirs.
Their’s	Incorrect spelling	The choice is their’s.

If you are writing for school, work, a website, an email, or any polished content, always use theirs.

What Does Theirs Mean?

Theirs means belonging to them. It replaces a noun phrase, so you do not need to say the noun again.

Examples:

• Our apartment is small, but theirs is huge.
• My seats are in the back; theirs are near the front.
• The responsibility is theirs now.
• That garden must be theirs.
• These tickets are ours, and those are theirs.

In each sentence, theirs stands alone. It does not come before a noun. You would not say theirs house or theirs car. Instead, theirs replaces the full idea: their house, their car, their seats, or their responsibility.

What Does Their’s Mean?

Their’s does not have a correct use in standard English. It is a common mistake caused by confusion about apostrophes. Many people know apostrophes can show ownership, so they try to add one to their. But possessive pronouns already show ownership by themselves.

Examples:

• Incorrect: That dog is their’s.
• Correct: That dog is theirs.
• Incorrect: The mistake was their’s.
• Correct: The mistake was theirs.

The apostrophe does not make the word more possessive. It only makes it incorrect.

Spelling Structure: Why Theirs Has No Apostrophe

The word theirs is built as a possessive pronoun. It already means belonging to them. Because possession is already built into the word, you do not add an apostrophe.

Compare it with other possessive pronouns:

• mine
• yours
• hers
• ours
• theirs

None of these words use apostrophes. You do not write your’s, her’s, our’s, or their’s. The correct forms are yours, hers, ours, and theirs.

This is the most important spelling pattern to remember: possessive pronouns do not need apostrophes.

Their vs Theirs

Their and theirs are both possessive, but they work differently in a sentence.

Use their before a noun.

• Their house is nearby.
• Their car is parked outside.
• Their idea was successful.

Use theirs when the noun is not repeated.

• The house is theirs.
• The car is theirs.
• The idea was theirs.

Form	How It Works	Example
Their	Comes before a noun	Their dog is friendly.
Theirs	Stands alone	The dog is theirs.

This distinction helps prevent mistakes. If a noun comes right after the word, use their. If the word stands alone, use theirs.

When to Use Theirs

Use theirs when something belongs to them and you do not want to repeat the noun.

• This table is ours, and that one is theirs.
• The larger room is theirs.
• The problem is theirs to solve.
• Our plans changed, but theirs stayed the same.
• The victory was theirs after months of practice.

A helpful test is to replace theirs with belonging to them. If the sentence still makes sense, theirs is correct.

• The decision is theirs.
• The decision belongs to them.

Common Mistakes

The most common mistake is adding an apostrophe because the sentence shows ownership.

Incorrect:

• The apartment is their’s.
• The blame is their’s.
• The black suitcase is their’s.

Correct:

• The apartment is theirs.
• The blame is theirs.
• The black suitcase is theirs.

Another mistake is using theirs before a noun.

Incorrect:

• Theirs house is beautiful.

Correct:

• Their house is beautiful.
• The house is theirs.

Remember: their goes before a noun, and theirs stands alone.

How to Remember Theirs

Use these memory tips:

• Theirs already means belonging to them.
• Their’s is wrong because possessive pronouns do not use apostrophes.
• If a noun comes after it, use their.
• If the word stands alone, use theirs.

A simple memory sentence is: Theirs owns the meaning, so it does not need an apostrophe.

You can also remember the group: yours, hers, ours, theirs. None of these words has an apostrophe. If your’s looks wrong, their’s should look wrong too.

Final Answer

Theirs is the correct possessive pronoun. It means something belongs to them. Example: The house is theirs.

Their’s is incorrect and should be avoided. To remember the spelling, compare it with yours, hers, and ours. Possessive pronouns already show ownership, so they do not need apostrophes.