Their Or Thier:(Meaning, Examples, And Grammar Rules) for 2026

Confused about whether to write their or thier? You’re not alone. Many people struggle with these similar-looking words, especially in fast typing or casual writing.

The good news is, there’s a simple rule to remember: “Their” is correct, while “thier” is always a misspelling.

This confusion often arises because the pronunciation doesn’t change, and our brains sometimes swap letters.

In this article, we’ll clear up the mystery, explore the word’s origin, compare British and American spelling, provide real-life examples, and guide you on which form to use depending on your audience. By the end, you’ll never mix up their and thier again.

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Their or Thier – Quick Answer

Quick Answer:

• Their → Possessive form of “they.” It shows ownership.
• Thier → Incorrect spelling; avoid using it.

Examples:

1. Their car is parked outside.
2. I like their new house.

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The Origin of Their or Thier

The word “their” comes from the Old Norse word “þeirra”, which means “of them.” It entered Middle English in the 13th century through Norse influence. Over time, English standardized the spelling to their, making thier a common typographical error rather than a valid word. This history explains why we sometimes see thier in informal writing it’s a natural letter swap caused by pronunciation patterns.

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British English vs American English Spelling

When it comes to their, there’s no difference in spelling between British and American English. Both use their consistently.

Word	British English	American English	Notes
Their	Their	Their	Correct in both versions
Thier	✗ Incorrect	✗ Incorrect	Always a typo

Unlike words like “colour/color” or “centre/center,” their remains the same globally, which simplifies usage.

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Which Spelling Should You Use?

Always use their it is correct in all forms of English. Avoid thier entirely.

Audience-based advice:

• US: Use their (correct in emails, essays, reports).
• UK/Commonwealth: Also their, no changes.
• Global English learners: Memorize their, as “thier” will appear wrong in professional writing and exams.

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Common Mistakes with Their or Thier

1. Incorrect: Thier house is big.
   Correct: Their house is big.
2. Incorrect: I like thier idea.
   Correct: I like their idea.
3. Confusing there, they’re, and their common in fast typing.
   • There → place (“The book is over there.”)
   • They’re → contraction of “they are” (“They’re happy today.”)
   • Their → possession (“Their dog is cute.”)

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Their or Thier in Everyday Examples

• Emails: “I’ve attached their report for review.”
• News: “Their performance in the finals was outstanding.”
• Social Media: “I love their outfit today!”
• Formal Writing: “The committee will review their findings.”

Tip: Reading aloud can help catch accidental thier mistakes.

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Their or Thier – Google Trends & Usage Data

Google search data shows:

• “Their” appears in over 50 million searches globally.
• “Thier” appears in about 500k searches, mostly from typing errors.
• Top countries searching for “their” include the USA, UK, Canada, and Australia.

This clearly indicates their is the universal standard, while thier is almost always a typo.

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Comparison Table: Their Variations

Variation	Correct?	Example
Their	✅ Correct	Their car is fast.
Thier	❌ Incorrect	Thier car is fast.
There	✅ Correct (different meaning)	The book is there.
They’re	✅ Correct (contraction)	They’re arriving soon.

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FAQs About Their or Thier

1. Q: Is “thier” ever correct?
   A: No, it’s always a typo.
2. Q: Can “their” be used in British English?
   A: Yes, it’s correct in both British and American English.
3. Q: How do I remember the correct spelling?
   A: Think “I before E” is wrong here. The correct form is their.
4. Q: What is the difference between “their” and “they’re”?
   A: “Their” shows possession, “they’re” is a contraction for “they are.”
5. Q: Is “thier” common in professional writing?
   A: No, it’s usually a typing error and should be corrected.
6. Q: Can spellcheck catch “thier”?
   A: Most modern spellcheckers will flag it as incorrect.
7. Q: Are there mnemonic tips for remembering “their”?
   A: Remember: the-IR, “IR” at the end think ownership.

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Conclusion

In summary, always use their for the possessive form of “they” and avoid thier, which is simply a common typo. The word’s history traces back to Old Norse, and its spelling has been standardized for centuries. Whether you’re writing emails, social media posts, essays, or professional reports, their is the universally accepted form in both British and American English. Knowing the difference between their, there, and they’re can prevent embarrassing mistakes and improve your writing credibility. By applying these tips, consulting real-life examples, and checking trends, you can confidently use their in all contexts and never confuse it with the incorrect thier again.

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