If you are wondering whether to write their or thier, the correct spelling is their. Thier is a common spelling mistake caused by reversing the letters e and i. Their is used to show possession or connection, as in “The students brought their books.” Thier has no standard grammatical use in modern English.
What Is the Difference Between Their and Thier?
The difference is simple: their is a correct English word, while thier is a misspelling of their.
Their is a possessive determiner. In plain English, it tells us who something belongs to or is connected with.
For example:
The children packed their bags.
The word their shows that the bags belong to the children.
Thier does not have a separate meaning in standard modern English. If you write “The children packed thier bags,” the reader can usually understand what you mean, but the spelling is incorrect.
The two forms look almost identical because they contain the same five letters. Only the order of e and i changes:
- Their: T-H-E-I-R
- Thier: T-H-I-E-R
This small difference is enough to make one form correct and the other incorrect.
Why Does Correct Spelling Matter?
A spelling mistake does not always change the meaning of a sentence. However, it can affect how clearly and carefully your writing is received.
Imagine writing an important email to a client:
Please send thier updated quotation.
The client may understand the sentence, but the misspelling can distract from your message.
The same issue can appear in:
- School assignments
- University essays
- Business emails
- Website content
- Job applications
- Reports and presentations
- Social media captions
Correct spelling helps readers focus on your ideas rather than small errors. It also makes your writing easier to proofread and edit.
The Core Rule
Use their when you mean belonging to them or associated with them. Never use thier as its spelling.
Remember the correct letter order:
T-H-E-I-R
The e comes before the i.
Their is also used with singular they. For example:
Every applicant should bring their identification.
Here, their refers to one applicant, not necessarily several people. Singular they is a standard feature of modern English, and their can refer to one person whose gender is unknown, unspecified, or who uses they/them pronouns.
How to Use Their Correctly
Their Before a Noun
Their usually comes before a noun to show possession or association.
A noun is a word for a person, place, thing, or idea.
Examples:
- Their house
- Their teacher
- Their business
- Their children
- Their decision
In each phrase, their tells us who the noun is connected with.
Read More: Pricy vs Pricey: Which Spelling Is Correct?
Their With a Singular Person
Their does not always refer to a group.
For example:
Someone left their phone on the table.
The word someone refers to one person. Their shows that the phone belongs to that person.
Another example:
Each employee must update their password.
This means each employee must update that employee’s password.
Their With Animals and Things
Their can also refer to animals or groups of things.
The birds returned to their nest.
The companies announced their results.
The nest is associated with the birds, and the results belong to the companies.
Their in Questions
Their can appear in questions when asking about ownership or association.
Where are their bags?
Did you read their report?
Who is responsible for their project?
In each sentence, their describes something connected with a person or group.
Correct Examples of Their
The following examples show how to use their in everyday, academic, and professional English.
- The students opened their notebooks before the lesson.
- My neighbors painted their house last weekend.
- The company announced their new office location.
- The children placed their shoes beside the door.
- Each applicant should check their email regularly.
- The manager asked the employees to submit their reports.
- Our friends invited us to their wedding.
- The researchers published their findings in a journal.
- The players celebrated their victory after the match.
- The customers received their orders on Monday.
- The students explained their answers during the exam.
- The family returned to their hometown after many years.
In every example, their identifies the people or group connected with the noun that follows.
Incorrect vs. Correct: Their and Thier
| Incorrect | Correct | Why |
|---|---|---|
| The students forgot thier books. | The students forgot their books. | Their is the correct possessive spelling. |
| Please check thier email. | Please check their email. | Their refers to the email belonging to them. |
| The team finished thier project. | The team finished their project. | The e and i must appear in the correct order. |
| Everyone should bring thier ID. | Everyone should bring their ID. | Singular their is standard English. |
| The children cleaned thier room. | The children cleaned their room. | Their shows association with the children. |
| I read thier report yesterday. | I read their report yesterday. | Thier is not a standard English word. |
| The company changed thier policy. | The company changed their policy. | Their is used before the noun policy. |
| The birds returned to thier nest. | The birds returned to their nest. | Their is the correct possessive determiner. |
| The players wore thier uniforms. | The players wore their uniforms. | Their indicates that the uniforms belong to the players. |
| The guests left thier bags outside. | The guests left their bags outside. | The spelling must be T-H-E-I-R. |
Why Do People Write Thier Instead of Their?
1. The Letters Are Easy to Reverse
The most direct reason is letter-order confusion.
The correct word contains ei:
Their
The incorrect form contains ie:
Thier
Because the words are so similar, a writer may type the letters in the wrong order without noticing.
2. English Spelling Patterns Are Inconsistent
Many learners remember the spelling guideline “i before e except after c.” However, this is not a reliable rule for every English word.
Their is one of the words that does not follow that familiar pattern. Other examples include:
- Weird
- Foreign
- Leisure
- Height
This does not mean there is a special grammar rule for thier. It simply means that memorizing their as a complete word is safer than relying on a general spelling slogan.
3. Fast Typing
When people type quickly, their fingers may produce the wrong letter order.
This can happen in:
- Text messages
- Emails
- Social media posts
- School assignments
- Business documents
The writer may know the correct spelling but still make a typing error.
4. The Brain Recognizes the Word Too Quickly
Readers often recognize familiar words from their overall shape and context. This can make a small internal spelling error easy to miss during proofreading.
For example, someone may read a sentence containing thier and understand it as their without consciously noticing the mistake.
5. Translation Interference
Learners whose first language does not use the same spelling patterns as English may find the e-i order difficult to remember.
This is not a problem with intelligence or grammar knowledge. It is a common part of learning English spelling.
Common Mistakes Checklist
Mistake 1: Writing Thier
What happens: The letters e and i are reversed.
Why it happens: The two spellings look almost identical.
How to avoid it: Memorize the correct sequence: T-H-E-I-R.
Mistake 2: Using There for Possession
Incorrect:
The students left there bags at school.
Correct:
The students left their bags at school.
There is not the possessive form of they. Their is the correct choice when something belongs to or is associated with them.
Mistake 3: Using They’re for Possession
Incorrect:
They’re books are on the desk.
Correct:
Their books are on the desk.
They’re is a contraction of they are. It cannot replace their when you are showing possession.
Mistake 4: Assuming Singular Their Is Wrong
Incorrect assumption:
Their can only refer to several people.
Correct understanding:
Every customer should keep their receipt.
Singular their is standard English and is useful when referring to one person without specifying gender.
Mistake 5: Trusting Spellcheck Without Reading
Spellcheck can help identify many spelling errors, but it is not a replacement for proofreading. It may not identify every problem, especially when the mistake involves a correctly spelled word used in the wrong place.
Their in Real English
Their Before a Noun
Their is natural and standard when it comes before a noun.
The employees submitted their reports.
This is a normal way to express possession or association. The word their identifies which employees the reports belong to or are connected with.
Their in Everyday Conversation
Their is also common in ordinary speech.
Where are their keys?
The sentence sounds natural because their is the standard possessive form used with they. There is no reason to replace it with thier.
Read More: Tweek vs Tweak Difference: Which Spelling Is Correct?
Their With Singular They
Someone left their umbrella in the hallway.
This is natural modern English. The speaker does not need to know or mention the person’s gender. Singular their is used in everyday conversation, professional writing, and other standard contexts.
Their in Formal Writing
Their is fully appropriate in academic and professional writing.
The researchers compared their results with earlier studies.
There is no need to replace their with a different word simply because the sentence is formal.
American vs. British English
There is no spelling difference between American and British English for their.
| Feature | American English | British English |
|---|---|---|
| Correct spelling | Their | Their |
| Incorrect spelling | Thier | Thier |
| Meaning | Possession or association | Possession or association |
| Singular their | Used | Used |
| Pronunciation | Usually /ðer/ | Usually /ðeə/ |
The two varieties use the same spelling and grammatical function for their. There is no American form “thier” or British form “thier.”
Formal vs. Informal Usage
Their is appropriate in both formal and informal English.
| Context | Example |
|---|---|
| Formal email | Please review their proposal. |
| Academic writing | The authors explained their findings. |
| Workplace conversation | The team has finished their work. |
| Text message | I think they left their keys here. |
| Social media | Their new collection looks amazing. |
Thier should not be used as an alternative spelling in standard English, regardless of how formal or informal the writing is.
Their vs. There vs. They’re
Many people confuse their with there and they’re because these words sound alike in many varieties of English. They have different meanings and grammatical roles. (Our Languages)
| Word | Meaning | Example |
|---|---|---|
| Their | Belonging to or associated with them | Their car is outside. |
| There | A place, position, or existence | The car is over there. |
| They’re | They are | They’re waiting outside. |
| Thier | Incorrect spelling of their | ❌ Thier car is outside. |
Their
Use their to show possession or association.
The children packed their toys.
There
Use there to refer to a place or to introduce a statement about existence.
The books are over there.
There are five students in the room.
They’re
They’re means they are.
They’re coming tomorrow.
You can replace they’re with they are and the sentence should still make sense.
A Quick Comparison
They’re taking their bags over there.
This sentence contains all three correct forms:
- They’re = they are
- Their = belonging to them
- There = a place
Memory Trick: Their Contains Heir
A simple way to remember the spelling is to notice that their contains the word heir.
An heir is a person who inherits property or possessions.
THEIR → HEIR → POSSESSION
This helps connect the spelling with the meaning.
You can also remember:
THE + IR = THEIR
The word begins with the same letters as the.
Real-Life Situations
In a Job Interview
“The applicants should bring their identification documents.”
Their refers to the documents belonging to the applicants.
In a Meeting
“The managers shared their recommendations.”
Their shows that the recommendations came from the managers.
In an Email
“Please ask the customers to confirm their delivery address.”
Their refers to the customers and the address associated with them.
In a Text Message
“I think they left their umbrella here.”
Their identifies the umbrella belonging to them.
In an Exam
“Each student must write their answer clearly.”
Singular their refers to each student.
Expert Tips
- Learn their as a whole word rather than relying only on the “i before e” rule.
- When you see thier, check whether you intended to write their.
- Read your writing aloud, but remember that pronunciation will not distinguish their from there or they’re.
- Use the meaning test: does the word show possession or association? If yes, their may be correct.
- Use the replacement test for they’re: can you replace it with they are?
- Use the location test for there: does it refer to a place or introduce an existence statement?
- Pay special attention to their in important emails, reports, and assignments.
Quick Summary
Their is the correct spelling, and thier is a misspelling. Use their to show possession or association with people, animals, or groups. It usually appears before a noun, as in “their house” or “their ideas.” Their is also used with singular they, such as “Every student should bring their notebook.” There refers to a place or existence, while they’re means they are. Their has the same spelling and meaning in American and British English. The easiest way to remember it is to focus on the correct letter order: T-H-E-I-R. If you see thier in your writing, replace it with their.
FAQ
Is thier a real English word?
Thier is not the standard spelling of the possessive word their. In ordinary modern English, it is treated as a spelling mistake. Use their when you mean belonging to or associated with them.
What is the correct spelling: their or thier?
The correct spelling is their. The letters appear in this order: T-H-E-I-R.
How do you pronounce their?
Their is commonly pronounced /ðer/ in American English and /ðeə/ in many British English contexts. Pronunciation varies by accent, but the spelling remains the same.
Can I use their for one person?
Yes. Singular their is standard English. For example, “Someone left their phone” refers to one person without specifying gender.
Is their a possessive pronoun or adjective?
Their is traditionally called a possessive adjective in many grammar books. More precisely, it is a possessive determiner because it appears before a noun, as in their house. The related independent possessive form is theirs, as in “The house is theirs.”
Why is their spelled with ei?
Their has a historical spelling that does not follow the familiar “i before e” guideline. The safest approach is to memorize the word rather than rely on that rule.
Is thier ever correct in a sentence?
Not when you intend the standard possessive word their. Thier may appear as an unusual name or other proper noun, but that does not make it a valid alternative spelling of their.
Does spellcheck always catch thier?
Many spellcheckers identify thier as a spelling error. However, spellcheckers are not perfect, and writers should still proofread their work.
Can their refer to animals?
Yes. For example, “The dogs wagged their tails.” Their shows the connection between the dogs and their tails.
Is their used in formal writing?
Yes. Their is completely standard in academic, professional, and formal writing.
What is the difference between their and theirs?
Their usually comes before a noun: “Their car is new.” Theirs is an independent possessive form: “The car is theirs.”
Mini Quiz
| No. | Question | Answer | Explanation |
|---|---|---|---|
| 1 | Choose the correct spelling: “The students opened ___ books.” A. their B. thier | A. their | Their is the correct possessive spelling. |
| 2 | Fill in the blank: “Someone left ___ phone on the desk.” | Their | Singular their can refer to one person. |
| 3 | Correct the sentence: “The manager reviewed thier report.” | The manager reviewed their report. | Thier is a misspelling of their. |
| 4 | Choose the correct word: “___ going to visit their friends.” A. Their B. There C. They’re | C. They’re | They’re means they are. |
| 5 | Fill in the blank: “The bags are over ___.” | There | There refers to a place. |
| 6 | Correct the sentence: “They’re car is parked outside.” | Their car is parked outside. | Their shows possession. |
| 7 | Choose the correct spelling: “The company announced ___ new policy.” A. thier B. their | B. their | Their is the correct form before a noun. |
| 8 | Fill in the blank: “The children packed ___ toys.” | Their | Their shows that the toys belong to the children. |
| 9 | Correct the sentence: “Thier going to bring their books.” | They’re going to bring their books. | They’re means they are; their shows possession. |
| 10 | Which word means “they are”? A. Their B. There C. They’re | C. They’re | They’re is the contraction of they are. |
