Thier or Their:Which One Is Correct?

English learners across the world often search for “thier or their” because these two spellings look almost the same but only one of them is correct. This small spelling mistake is very common in emails, exams, social media posts, blogs, and even professional writing.

Many people type thier by accident because it sounds exactly like their when spoken. Autocorrect sometimes fails to catch it, which makes the confusion even worse.

People usually want a quick answer: Is thier a word or not? But they also want a clear explanation so they do not repeat the mistake again.

This confusion matters because “their” is a very common possessive word in English. Using the wrong spelling can make your writing look careless or unprofessional, even if the rest of your sentence is correct.

This article solves that problem completely. You will get a quick answer, word origin, British vs American spelling rules, common mistakes, real-life examples, usage trends, FAQs, and

professional advice. Everything is explained in very simple language so anyone can understand it easily. By the end, you will confidently know when to use their and why thier is wrong.

Thier or Their:Quick Answer

Their is the correct spelling.

Thier is incorrect and considered a spelling mistake in standard English.

Examples:

Their house is very big. ✅
I like their ideas. ✅

❌ Thier house is very big. ❌ I like thier ideas.

The Origin of Thier or Their

Understanding the origin of their helps explain why thier exists only as a mistake.

Origin of “Their”

The word their comes from Old Norse þeira, meaning belonging to them. It entered Middle English through Scandinavian influence and became a possessive pronoun. Over time, the spelling their became fixed and standardized in English.

Their is used to show possession, meaning something belongs to them.

Why “Thier” Exists

Thier has no historical origin as a correct English word. It exists mainly because:

People type quickly and swap letters
Confusion with spelling patterns
Influence of non-native English writing

In dictionaries and grammar rules, thier is always marked as incorrect.

British English vs American English Spelling

There is no difference between British English and American English when it comes to their.

British English: their
American English: their

Thier is incorrect in both varieties.

Comparison Table

Aspect	British English	American English
Correct spelling	their	their
Incorrect spelling	thier	thier
Meaning	possession	possession
Grammar rule	same	same

Which Spelling Should You Use?

You should always use “their”, no matter who your audience is.

Audience-Based Advice

US audience: Use their
UK/Commonwealth audience: Use their
Global audience: Use their

There is no situation where thier is correct in standard English writing.

Simple rule:

If you mean “belonging to them,” use their.

Common Mistakes with Thier or Their

Mistake 1: Typing error

❌ Thier car is parked outside. ✅ Their car is parked outside.

Mistake 2: Ignoring spellcheck

❌ Everyone forgot thier keys. ✅ Everyone forgot their keys.

Mistake 3: Confusing with “there” or “they’re”

❌ Their going to school. ✅ They’re going to school.

Thier or Their in Everyday Examples

Emails

Please submit their documents by Monday.
Their request has been approved.

News

The team celebrated their victory.
Citizens raised their concerns.

Social Media

I love their style 😍
Their new video is amazing!

Formal Writing

The company revised their policy.
Students must complete their assignments.

Thier or Their:Google Trends & Usage Data

Search data shows that “thier or their” is frequently searched in:

South Asia
Middle East
Africa
ESL-learning regions

The incorrect spelling thier appears mainly due to typing errors, while their dominates in published books, news articles, and professional writing worldwide.

Google Trends data suggests that searches spike:

During exam seasons
Among content writers and bloggers
When users doubt spelling correctness

This shows strong intent for quick confirmation and correct usage.

Comparison Table:Thier vs Their

Word	Correct?	Meaning	Usage
their	✅ Yes	belonging to them	Always use
thier	❌ No	none	Never use

FAQs

Is “thier” a real word?

No. Thier is not a correct English word.

Is “their” singular or plural?

Their can be used with both singular and plural nouns.

Can “their” be gender-neutral?

Yes. It is often used as a gender-neutral possessive.

Why do people write “thier”?

Mostly due to typing mistakes or spelling confusion.

Is “their” different from “there”?

Yes. Their shows possession, there shows place.

Is “their” used in formal writing?

Yes. It is completely acceptable and professional.

Will spellcheck catch “thier”?

Not always, which is why mistakes happen.

Conclusion

The confusion between thier or their is simple to solve once you know the rule. Their is the only correct spelling and is used to show possession. Thier has no grammatical value and

should never be used in standard English writing. This mistake usually happens because of fast typing, pronunciation habits, or lack of attention to spelling.

Whether you are writing an email, exam answer, blog post, social media caption, or formal document, using their correctly makes your writing look clear and professional. There is no British or American difference to worry about, which makes the rule even easier to remember. If the word means belonging to them, then their is always the right choice.

By following the examples, tables, and tips in this guide, you can completely avoid this common error. Small spelling fixes like this can greatly improve your overall English writing quality and confidence.