Theirs or Their’s: Which Spelling Is Actually Correct?

Theirs is the correct spelling of the possessive pronoun. Their's is incorrect because possessive pronouns do not need an apostrophe.

Have you ever stopped while writing a sentence and wondered whether to use theirs or their’s? You are not alone. Many students, writers, and English learners make this mistake.

Imagine writing a school essay or a work email. You want to say that a book belongs to your friend. You type, “This book is their’s.” The sentence may look right at first, but it contains a spelling error.

As an English teacher and writer, I often see how small spelling mistakes can make writing less clear. Words like theirs, theirs, and their can be confusing because they look alike and have related meanings. Yet each word follows a different rule.

The good news is that this rule is easy to learn. Once you understand why theirs has no apostrophe, you can use it with confidence in essays, emails, reports, and everyday messages.

In this guide, you will learn the correct spelling, meaning, grammar rules, common mistakes, and real-life examples. You will also discover a simple trick to help you remember the right form.

Theirs or Their’s: Quick Answer

Theirs is the correct spelling. It means that something belongs to two or more people, or to people whose gender is not specified. Their’s is not a standard English word.

For example:

• Correct: That house is theirs.
• Incorrect: That house is their’s.
• Correct: The final decision was theirs.
• Incorrect: The final decision was their’s.

The rule is simple: use theirs without an apostrophe when you show ownership.

Other possessive pronouns follow the same pattern. These include mine, yours, hers, and ours.

For example:

• This bag is mine.
• That seat is yours.
• The blue car is hers.
• The choice is ours.
• The garden is theirs.

None of these possessive pronouns needs an apostrophe.

The Origin and Background of Theirs

The word theirs developed from older forms of English used to show possession. It belongs to a group of words that help us identify who owns something.

English has two common ways to show ownership. One uses a noun with a possessive form, such as the students’ books. The other uses a possessive pronoun, such as the books are theirs.

Over time, English developed a clear pattern for possessive pronouns. Words such as mine, yours, hers, and theirs stand on their own. They do not need an apostrophe to show ownership.

Why, then, do people write their’s?

The main reason is that many people learn to use apostrophes to show possession. For example, Sarah’s book means the book belongs to Sarah. This rule works with nouns, but it does not apply to possessive pronouns.

Compare these examples:

• Sarah’s book: The apostrophe shows possession.
• Their book: The word their comes before a noun.
• The book is theirs: The word theirs replaces the noun phrase.
• The book is their’s: Incorrect spelling.

The difference becomes clear when you learn which type of word you are using.

Theirs Explained: Key Differences and Variations

To understand theirs, you should also learn the difference between their, theirs, and their’s.

1. Theirs

Theirs is a possessive pronoun. It shows that something belongs to a person or group.

Examples:

• That classroom is theirs.
• The red bags are theirs.
• This idea was theirs, not ours.

You can use theirs without naming the thing again after it.

For example, instead of saying, “This is their house, and that is their house too,” you can say, “This house is theirs, and that one is theirs too.”

2. Their

Their is a possessive determiner. It comes before a noun to show who owns something.

Examples:

• Their house is near the park.
• The children forgot their bags.
• The team shared their plans.

Notice that their needs a noun after it in these examples. You say their car, not their is parked outside.

3. Their’s

Their’s is an incorrect spelling in standard English. It is not the correct possessive form of their.

Examples:

• Incorrect: The house is their’s.
• Correct: The house is theirs.
• Incorrect: That choice was their’s.
• Correct: That choice was theirs.

Do not add an apostrophe to theirs, even when you are talking about ownership.

Comparison Table

Term	Meaning	When to Use	Region/Context
Theirs	Belonging to them	When the possessive pronoun stands alone	Standard English
Their	Belonging to them	Before a noun	Standard English
Their’s	Incorrect spelling	Do not use it	Nonstandard error

Which Version Should You Use?

The answer is simple: always use theirs, not their’s, when you need the possessive pronoun.

Here is how to use the correct form in different situations.

For Students

Use theirs in schoolwork, essays, and exams.

Example:

“The notebooks on the desk are theirs.”

This sentence is grammatically correct because theirs shows ownership without an apostrophe.

For Teachers and English Learners

Teach yourself to recognize the difference between a possessive determiner and a possessive pronoun.

• Their students are ready.
• The students are theirs.

In the first sentence, their comes before the noun students. In the second, theirs stands alone.

For Professional Writers

Use theirs in reports, business emails, formal documents, and presentations.

Example:

“The final responsibility is theirs.”

This wording is clear, concise, and grammatically correct.

For Social Media and Casual Messages

The same rule applies to text messages and online posts. Informal writing does not make their’s correct.

Correct: “Those seats are theirs!”

Incorrect: “Those seats are their’s!”

Best rule: Use their before a noun and theirs when the possessive word stands alone.

Common Mistakes with Theirs

Even experienced writers can make apostrophe mistakes. These are some common errors and how to fix them.

Mistake 1: Adding an Apostrophe to Theirs

Incorrect: The choice is their’s.

Correct: The choice is theirs.

Why it happens: People often add apostrophes to words that show ownership. However, possessive pronouns follow a different rule.

Mistake 2: Confusing Their and Theirs

Incorrect: The children left theirs bags at school.

Correct: The children left their bags at school.

Why it happens: Both words show ownership, but their comes before a noun. In this sentence, the noun is bags.

Mistake 3: Using Theirs Before a Noun

Incorrect: Theirs car is new.

Correct: Their car is new.

Why it happens: Writers sometimes mix up the possessive determiner and the possessive pronoun. Remember that theirs usually stands alone.

Mistake 4: Thinking Apostrophes Always Show Ownership

Incorrect: The books are their’s.

Correct: The books are theirs.

Why it happens: An apostrophe often shows possession in nouns, as in the teacher’s desk. But possessive pronouns such as hers and theirs do not use one.

Mistake 5: Confusing Theirs with There’s

Incorrect: The bag over there is there’s.

Correct: The bag over there is theirs.

Why it happens: Theirs and there’s sound similar in some accents, but they have different meanings.

• Theirs means belonging to them.
• There’s is a contraction of there is or there has.

Example: “There’s a bag on the chair” means a bag is present. “The bag is theirs” means it belongs to them.

Theirs in Real-World Examples

Seeing a word in different situations can help you remember how to use it.

1. In a Professional Email

Example:

“Thank you for reviewing both proposals. The final decision is theirs, and we will support the selected team.”

Why it works: Theirs shows that the decision belongs to the people or group mentioned earlier.

2. In a News Article

Example:

“The players celebrated after the victory, saying the achievement was theirs.”

Why it works: Theirs refers to the players and shows that the achievement belongs to them.

3. In a Social Media Post

Example:

“These wonderful memories are ours, but the credit for the project is theirs!”

Why it works: Both ours and theirs are possessive pronouns. Neither needs an apostrophe.

4. In a Formal Report

Example:

“The team completed its assigned tasks. The remaining responsibilities are theirs.”

Why it works: The word theirs refers to the team members or people discussed earlier.

5. In Everyday Conversation

Example:

“Is that your jacket?”

“No, it’s theirs.”

Why it works: Theirs replaces a longer phrase, such as “It belongs to them.”

6. In a School Essay

Example:

“Every group presented its work. The judges said the strongest ideas were theirs.”

Why it works: Theirs identifies who the ideas belong to without repeating the full noun phrase.

Theirs: Data, Trends, and Usage

The confusion between theirs and their’s is part of a wider pattern in English spelling. Many writers know that apostrophes can show possession, but they may not know that possessive pronouns are an exception.

People searching for theirs or their’s usually want a quick answer to one question: which spelling is correct?

This makes the keyword an informational search term. Readers are looking for a spelling rule, a definition, or examples they can use immediately.

Who Searches for This Topic?

The topic can help several groups:

• Students who want to avoid spelling and grammar errors.
• English learners who are learning possessive pronouns.
• Teachers who need simple examples for grammar lessons.
• Professional writers who want clear and correct writing.
• Everyday users who want to check a word before sending a message.

Why Does This Confusion Matter?

A small apostrophe can change whether a word is correct in standard English. Repeated errors may distract readers from the meaning of a sentence.

The good news is that this mistake is easy to prevent. Learning a single rule can help you write more clearly in school, at work, and online.

There is no verified search-volume figure provided here, so exact numbers or regional rankings should not be assumed. However, the spelling question has a clear educational purpose and can be answered with a simple rule and practical examples.

Standalone Comparison Table: Theirs or Their’s?

Term/Variant	Meaning	Region/Context	Best Used When
Theirs	Belonging to them	Standard English	Showing ownership without a following noun
Their	Belonging to them	Standard English	Showing ownership before a noun
Their’s	Incorrect spelling	Nonstandard usage	Avoid in all standard writing
There’s	There is or there has	Standard English	Describing existence or an event
Theirs’	Incorrect spelling	Nonstandard usage	Do not use this form

The main distinction is between their and theirs. Both show ownership, but they serve different grammatical roles. Their’s is not a correct alternative to either word.

Frequently Asked Questions

Q: Is it theirs or their’s?

A: Theirs is correct. Their’s is a spelling error because possessive pronouns do not use apostrophes.

Q: What does theirs mean?

A: Theirs means belonging to them. For example, “The blue car is theirs” means that the blue car belongs to them.

Q: How do you use theirs correctly in a sentence?

A: Use theirs when you want to show ownership without repeating the noun. For example, “Our seats are here, and theirs are near the door” would be incorrect if you mean the possessive pronoun alone before a noun. The correct version is “Our seats are here, and theirs are near the door” only when theirs refers to their seats and stands independently; before the noun seats, use their seats.

Q: What is the difference between their and theirs?

A: Their comes before a noun, as in “their house.” Theirs stands alone, as in “the house is theirs.”

Q: Is their’s acceptable in formal writing?

A: No. Their’s is not accepted as the standard possessive form. Use theirs in formal writing, academic work, business communication, and everyday messages.

Q: Where does the word theirs come from?

A: Theirs developed from older English forms used to show possession. It belongs to the group of possessive pronouns that includes mine, yours, hers, and ours.

Q: Can I use theirs in a professional email?

A: Yes. Theirs is correct in professional emails whenever you need to show ownership. For example, “The final decision is theirs” is clear and professional.

Q: Why doesn’t theirs have an apostrophe?

A: English possessive pronouns follow a special rule. Words such as hers, yours, ours, and theirs already show possession, so they do not need an apostrophe.

Q: Is theirs singular or plural?

A: Theirs can refer to one person or more than one person, depending on the context. For example, it can refer to one person whose gender is not specified or to a group of people.

Q: What is a simple trick to remember theirs?

A: Remember this phrase: “Theirs has no apostrophe.” You can also compare it with hers, yours, and ours. None of these possessive pronouns needs an apostrophe.

Conclusion

The difference between theirs and their’s is simple once you know the rule. Theirs is the correct spelling, while their’s is incorrect in standard English.

Remember these key points:

• Use theirs to show ownership when the possessive pronoun stands alone.
• Use their before a noun, such as their books or their home.
• Never add an apostrophe to theirs.
• Do not confuse theirs with there’s, which means there is or there has.

You do not need to memorize a long grammar lesson to get this right. Just remember that possessive pronouns such as mine, yours, hers, ours, and theirs do not use apostrophes.

The next time you write about something that belongs to another person or group, pause for a moment and check your spelling. A small change can make your writing more accurate and professional.

Yours or Your’s: The Easy Way to Get It Right