Many English learners and even native speakers often stumble upon the words “their” and “thier.” You might have seen sentences like “Their going to the store” or “Thier house is big” and wondered which is correct. Understanding this simple yet important difference can dramatically improve your writing and speaking skills.
The confusion usually arises because the correct word, “their,” sounds similar to the misspelled “thier.” While one is standard English, the other is simply a typographical error. This small mistake, however, can affect the clarity and professionalism of your writing.
Whether you are writing for a UK audience or a US one, mastering this distinction is essential. Both British English and American English use “their” identically, but “thier” is universally considered incorrect. Knowing the correct form ensures your communication is clear, polished, and understood worldwide.
Quick Answer
The correct word is “their.”
- Their is a possessive adjective that shows ownership. For example:
- “Their car is parked outside.”
- “I like their style.”
- “Their car is parked outside.”
- Thier is incorrect and should never be used in formal or informal writing. It is simply a misspelling of “their.”
In short: always use “their” when you want to indicate possession.
Meaning of the Correct Form: “Their”
“Their” is a possessive adjective used to show that something belongs to or is associated with a group of people, animals, or things.
Examples in British English (UK):
- “Their garden is full of roses.”
- “The children forgot their homework.”
- “I admire their dedication to the project.”
Examples in American English (US):
- “Their apartment is in New York City.”
- “The team celebrated their victory.”
- “I respect their opinion on the matter.”
As you can see, the usage of “their” is identical in UK and US English. The meaning never changes it always denotes possession.
Key Notes:
- Position in sentence: Usually comes before a noun. (“Their house,” not “house their.”)
- Pronunciation: /ðɛr/ (sounds like “thair”)
Meaning of the Incorrect Form: “Thier”
“Thier” is simply a common misspelling of “their.”
Many people type “thier” because they are trying to spell quickly or are unsure of the letter order. This error is purely orthographic; it has no meaning in English.
Incorrect Examples:
- “Thier car is blue.” ❌
- “I like thier dog.” ❌
- “Thier opinion matters.” ❌
Notice that in all cases, replacing “thier” with “their” corrects the sentence.
Tip: A simple trick is to remember the correct order of letters: “i” comes after “e” only in “their” when referring to possession.
Keyword Comparison / Key Differences
| Feature | Their | Thier |
| Correct? | ✅ Yes | ❌ No |
| Meaning | Possessive adjective (ownership) | None; misspelling |
| Usage | “Their dog is friendly.” | Incorrect: “Thier dog is friendly.” |
| UK English | Same as US English | Incorrect in UK English |
| US English | Same as UK English | Incorrect in US English |
| Common Confusion | Often confused with “there” or “they’re” | Typo due to fast typing |
Remember: Confusing “their” with “thier” is always a spelling mistake. Both UK and US English follow the same rules.
Common Mistakes People Make
Even experienced writers sometimes make errors with “their”. The most common mistakes include:
- Using “thier” instead of “their”
- ❌ “Thier house is beautiful.”
- ✅ “Their house is beautiful.”
- ❌ “Thier house is beautiful.”
- Confusing “their” with “there”
- ❌ “Their going to the cinema.”
- ✅ “They’re going to the cinema.”
- ❌ “Their going to the cinema.”
- Confusing “their” with “they’re”
- ❌ “Their happy about the news.”
- ✅ “They’re happy about the news.”
- ❌ “Their happy about the news.”
- Forgetting the possessive context
- ❌ “I saw their.” (incomplete)
- ✅ “I saw their cat.”
- ❌ “I saw their.” (incomplete)
- Switching UK/US spellings incorrectly
- Fortunately, “their” is consistent in both forms, so this is rarely an issue.
- Fortunately, “their” is consistent in both forms, so this is rarely an issue.
Correct Usage in Sentences
Examples for UK English:
- “Their flat is near the station.”
- “The students revised for their exams.”
- “I visited their office in London.”
- “Their team won the football match.”
- “We admired their traditional customs.”
Examples for US English:
- “Their house is on Main Street.”
- “The children left their backpacks in the classroom.”
- “I like their approach to problem-solving.”
- “Their team is playing in the championship.”
- “We enjoyed their hospitality during our visit.”
Tips for Practice:
- Replace “thier” with “their” whenever you spot it.
- Always check if you mean possession before writing.
Tips to Remember the Correct Usage
- Mnemonic Trick:
- “Their” has “heir” inside it → ownership/possession
- Example: “Their heirloom is valuable.”
- Example: “Their heirloom is valuable.”
- “Their” has “heir” inside it → ownership/possession
- Check the sentence:
- If you want to show ownership, use “their.”
- If the word refers to a place, it’s usually “there.”
- If it means they are, it’s “they’re.”
- If you want to show ownership, use “their.”
- Visual Reminder:
- Their = possession
- There = location
- They’re = they are
- Their = possession
- Typing Tip:
- Slow down while typing. “i” always comes after e in their.
- Slow down while typing. “i” always comes after e in their.
- UK vs US Note:
- Both English varieties use “their” in the same way. No regional changes needed.
- Both English varieties use “their” in the same way. No regional changes needed.
FAQs About “Their or Thier”
1. Is “thier” ever correct?
- No. “Thier” is always a misspelling of “their.”
2. Can I use “their” for singular nouns?
- Yes. English now commonly uses singular “their” to refer to a person of unknown gender.
- Example: “Someone left their umbrella.”
- Example: “Someone left their umbrella.”
3. How do I avoid confusing “their” and “there”?
- Remember: their = ownership, there = place.
4. Is “their” pronounced differently in UK and US English?
- No, it’s pronounced the same: /ðɛr/.
5. Why do people write “thier” by mistake?
- Usually a typing error or misunderstanding of the spelling.
6. Can “their” be used for animals or objects?
- Yes. Example: “The cats licked their paws.”
7. Are there any differences in using “their” in formal vs informal writing?
- No. “Their” is always correct for possession, in both casual and professional contexts.
Conclusion
Understanding the difference between “their” and “thier” is essential for clear, professional, and grammatically correct writing. “Their” always indicates ownership and is universally accepted in both UK and US English, while “thier” is simply a misspelling.
To avoid mistakes, remember the mnemonics, double-check your sentences for possession, and be mindful of similar words like there and they’re. By mastering their, you’ll write with confidence and clarity, impressing readers in both British and American English contexts.
