Is it their or thier? If you have ever mixed up these letters while writing a message, email, or school assignment, you are not alone. Their is the correct spelling, while thier is a misspelling in standard English. The difference is simply the order of two letters, but getting them right helps your writing look clear and professional.
In this guide, I will explain why their is correct, how to remember its spelling, and how to distinguish it from there, they’re, and theirs. You will also find practical sentence examples, a simple decision guide, common mistakes, and a short spelling exercise to help you use the right word confidently.
Quick Answer: Their or Thier?
Their is correct. Thier is incorrect in standard English. Use their to show that something belongs to or is associated with someone or something. There is no standard spelling difference in which thier has a separate meaning.
| Word | Correct spelling? | Meaning | Example |
| Their | Yes | Shows possession or association | They brought their lunch. |
| Thier | No | A spelling mistake | They brought thier lunch. |
Correct spelling: T-H-E-I-R.
For example, write “The employees submitted their reports,” not “The employees submitted thier reports.”
If you remember only one thing from this article, remember that the e comes before the i in their.
What Does Their Mean?
Their is a possessive determiner. It tells readers that something belongs to, or is connected with, people, animals, or things already mentioned or understood from the context.
For example, in the sentence “The children packed their bags,” the word their connects the bags to the children. It answers the question, “Whose bags?”
Here are more examples:
- The students completed their assignments before the deadline.
- My neighbors invited us to their house.
- The company updated its website and improved their customer support.
- The birds returned to their nests before sunset.
- Each applicant must provide their contact details.
In the final example, their refers to one applicant rather than a group. This is an accepted use of singular they, which is explained later in this article.
How to Use Their Correctly in a Sentence
Use their before a noun when you want to show possession or association.
In everyday conversation: “They left their jackets in the car.”
In a school assignment: “Students should review their notes before the examination.”
In a work email: “Please save your files in their designated folders.”
In a business context: “Customers can check their order status online.”
In a personal message: “My friends are celebrating their anniversary tonight.”
Each sentence uses their to connect a person or group with something related to them. The noun that follows makes the relationship clear.
Why Is Thier Incorrect?
Thier is a spelling error because the letters in their have been placed in the wrong order. Standard English uses their, not thier, to show possession.
The mistake can happen when someone types quickly or remembers the word incorrectly. The familiar rhyme “i before e, except after c” may also cause confusion, because English spelling has many exceptions to general patterns.
Compare these words:
- Their: Correct spelling.
- Thier: Incorrect spelling in standard English.
- Believe: Correct spelling.
- Receive: Correct spelling.
The letter order in their should be learned as part of the word rather than determined by applying a spelling rhyme mechanically.
An Easy Trick to Remember Their
Try breaking the word into two parts:
THEIR = T + HEIR
The word heir has the letters E-I in that order. Remembering this familiar word can help you recall the spelling of their.
For example:
- Correct: They forgot their tickets.
- Incorrect: They forgot thier tickets.
Another useful method is to write the correct word three times and use it in a sentence: “Their house is near the park.” This reinforces the correct letter order.
You can also enable spell-checking in your word processor. It will often flag thier as an error, although you should still proofread important documents yourself.
Their vs. Thier: What Is the Difference?
The difference is not one of meaning, pronunciation, or grammatical function. It is a matter of correct spelling.
| Feature | Their | Thier |
| Standard spelling | Correct | Incorrect |
| Meaning | Possession or association | No standard English meaning |
| Grammar | Possessive determiner | Not a standard grammatical form |
| Suitable for formal writing | Yes | No |
| Example | Their car is outside. | Thier car is outside. |
If you encounter thier in an email, assignment, or online article, it is usually a typo that should be corrected to their when possession is intended.
Their, There, and They’re: How to Tell Them Apart
The words their, there, and they’re often cause confusion because they sound alike in many English accents. However, each word serves a different purpose.
Their: Possession or Association
Use their when referring to something belonging to or associated with a person or group.
Example: The players collected their equipment after practice.
The equipment is associated with the players.
There: A Place or Existence
Use there to refer to a place or to introduce the existence of something.
Examples:
- Your phone is over there.
- There is a meeting at noon.
- We left the boxes there yesterday.
In the first and third examples, there refers to a location. In the second, it introduces the existence of a meeting.
They’re: A Short Form of They Are
They’re is a contraction of they are. The apostrophe indicates the missing letters.
Examples:
- They’re waiting outside. (They are waiting outside.)
- They’re ready for their presentation. (They are ready for their presentation.)
- They’re bringing their bags over there.
The final example shows all three words working together. They’re means “they are,” their indicates possession, and there identifies a location.
Comparison Table: Their vs. There vs. They’re
| Word | Meaning | Simple test | Example |
| Their | Possession | Does it show whose? | Their dog is friendly. |
| There | Place or existence | Does it refer to where or introduce something that exists? | There is a dog outside. |
| They’re | They are | Can you replace it with “they are”? | They’re walking home. |
| Thier | Misspelling | Correct the letter order | Their dog is friendly. |
A Simple Decision Guide
When you are unsure which word belongs in a sentence, follow these steps:
- Check for possession. If the word identifies whose belongings, ideas, or responsibilities are being discussed, use their.
- Try expanding the contraction. If replacing the word with “they are” makes sense, use they’re.
- Check for location or existence. If the sentence refers to a place or introduces something that exists, use there.
- Check the spelling. If you wrote thier while intending possession, change it to their.
For example:
Incorrect: Thier going to leave there bags over their.
Correct: They’re going to leave their bags over there.
This correction works because each word has a clear role in the sentence.
Their vs. Theirs: What Is the Difference?
Although their and theirs both express possession, they are not interchangeable in every sentence.
Their is a possessive determiner that comes before a noun.
Example: That is their office.
Theirs is a possessive pronoun that can stand alone instead of repeating the noun.
Example: That office is theirs.
Compare these sentences:
- This is their car.
- This car is theirs.
- Their presentation was excellent.
- The presentation was theirs.
The important rule is simple: use their before the noun you are identifying, and use theirs when the possessive word stands on its own.
Do not write “That car is their” when you mean that the car belongs to them. The correct sentence is “That car is theirs.”
Is Their Singular or Plural?
Their is commonly used with plural they, but it can also refer to one person. This second use is called singular they.
Their for More Than One Person
When a group owns or shares something, their shows that relationship.
Example: The teachers prepared their lessons for the new term.
Here, their refers to several teachers.
Their for One Person
Singular their is useful when a person’s gender is unknown, when the gender is irrelevant, or when the person uses they/them pronouns.
Examples:
- Someone left their umbrella in the reception area.
- Every student should bring their own notebook.
- Alex said their appointment had been moved.
- The author discussed their latest book.
In the first example, the writer does not know who left the umbrella. In the third, their refers to Alex, one person.
Oxford Learner’s Dictionaries recognizes singular uses of they, them, and their. The form is an established part of modern English, though individual style guides may have preferences about particular constructions.
Common Mistakes With Their
Understanding the spelling is only part of writing accurately. You also need to choose the correct word for the meaning you want to express.
Mistake 1: Writing Thier Instead of Their
Incorrect: The manager reviewed thier reports.
Correct: The manager reviewed their reports.
The correction is simple: place E before I.
Mistake 2: Using Their Instead of They’re
Incorrect: Their going to call us later.
Correct: They’re going to call us later.
The correct sentence means “They are going to call us later.” Since they are fits, they’re is the right choice.
Mistake 3: Using Their Instead of There
Incorrect: Their is a problem with the printer.
Correct: There is a problem with the printer.
The sentence introduces the existence of a problem, so it needs there.
Mistake 4: Using Their Instead of Theirs
Incorrect: That desk is their.
Correct: That desk is theirs.
The possessive word stands alone, so theirs is required.
Mistake 5: Choosing a Word Based Only on Sound
Incorrect spelling choices often occur because the words sound alike. However, pronunciation alone cannot tell you whether to use their, there, or they’re.
Instead, identify the meaning first. Ask whether you are showing possession, referring to a place, or saying “they are.” This method is more dependable than relying on how the sentence sounds.
How to Correct Their and Thier in Real Writing
Knowing the rule is useful, but applying it during proofreading makes the difference in everyday writing.
In Text Messages
Incorrect: I think thier car is blocking the entrance.
Correct: I think their car is blocking the entrance.
The correction makes the message look more polished without changing its meaning.
In School Assignments
Incorrect: Every student should submit thier homework on time.
Correct: Every student should submit their homework on time.
Here, their is singular because it refers to each student. The sentence is a common example of singular they in general instructions.
In Work Emails
Incorrect: Please ask the employees to update thier contact details.
Correct: Please ask the employees to update their contact details.
This is a simple proofreading correction that helps keep professional communication clear.
In Business Documents
Incorrect: Customers can manage thier accounts through the website.
Correct: Customers can manage their accounts through the website.
A misspelling does not necessarily make a message impossible to understand, but correcting it improves the quality and professionalism of the document.
Practice Exercise: Can You Choose the Correct Word?
Test your understanding with these sentences. Choose the word that fits the meaning.
- The students submitted ___ assignments.
- A. thier
- B. their
- C. they’re
- ___ going to arrive at six.
- A. Their
- B. There
- C. They’re
- The keys are over ___.
- A. there
- B. their
- C. thier
- That blue backpack is ___.
- A. their
- B. theirs
- C. they’re
- Someone left ___ phone on the desk.
- A. their
- B. there
- C. they’re
Answers and Explanations
- B. Their — It shows that the assignments belong to the students.
- C. They’re — The sentence means “They are going to arrive at six.”
- A. There — It identifies the location of the keys.
- B. Theirs — The possessive word stands alone without a noun after it.
- A. Their — Singular their refers to an unidentified person.
If you got all five correct, you understand the main differences. If you missed one, review the comparison table and focus on the meaning of the word rather than its sound.
Frequently Asked Questions
Is their or thier correct?
Their is correct, while thier is a spelling mistake in standard English. Use their to show possession or association.
Why do people spell their as thier?
The mistake usually happens when the letters E and I are reversed. It may occur during fast typing or when someone misremembers the spelling.
Is thier a real English word?
Thier is not a standard English word with an accepted grammatical meaning. In ordinary writing, it should be corrected to their when possession is intended.
How do I remember the spelling of their?
Remember the sequence T-H-E-I-R or use the mnemonic “T + HEIR.” The word heir contains E-I in the correct order, which can help you recall the spelling.
What is the difference between their and they’re?
Their shows possession, while they’re means they are. For example, “Their house is nearby” and “They’re walking home.”
What is the difference between their and there?
Their expresses possession or association, while there refers to a place or introduces the existence of something. For example, “Their bags are there.”
What is the difference between their and theirs?
Their comes before a noun, as in “their house.” Theirs stands alone, as in “The house is theirs.”
Can their refer to one person?
Yes. Singular their can refer to someone whose gender is unknown or to a person who uses they/them pronouns. For example, “Someone forgot their jacket.”
Is their a possessive pronoun?
In traditional grammar, their is classified as a possessive determiner because it comes before a noun. Theirs is the possessive pronoun that can stand alone.
How can I check whether I have written thier by mistake?
Use your word processor’s spell-checking feature and proofread important text. If you see thier and mean possession, correct it to their.
Final Verdict: Their or Thier?
Their is the correct spelling; thier is a misspelling. Use their when showing that something belongs to or is associated with someone or something. Remember the letter order, and distinguish it from there, they’re, and theirs by checking the meaning of your sentence.
You do not need a complicated spelling rule to get this right. Remember T-H-E-I-R, proofread your writing, and use the word that matches your intended meaning. With that simple habit, you can avoid this common error in school assignments, personal messages, and professional communication.
I am Celeste Rowan, an English writer passionate about helpful information, thoughtful ideas, and practical life guidance. I enjoy researching topics from different perspectives and presenting them in a way that feels clear and approachable. Through my writing, I aim to answer common questions, explain unfamiliar subjects, and give readers information they can genuinely use. I always try to make my work informative without making it complicated.
Books:
- A Clearer Way to Understand Life
- Simple Answers to Everyday Questions
Nolan Everhart
Marlowe Bennett