Thier Or Their: Which Spelling Is Correct?

Their is the correct spelling. Thier is not a real word in English, even though it looks like a reasonable guess. If you have ever typed thier and had it underlined in red, that is your spellchecker confirming this exact point.

The confusion usually comes from a spelling rule most of us learned as kids: i before e, except after c. Their seems to break that rule, so people flip the letters and end up with thier by mistake. It is one of the most common typos in English, right alongside definately and recieve.

Their: The Simple Definition

Their is a possessive pronoun. It shows that something belongs to a group of people, animals, or things.

You use it before a noun to say who owns that noun.

• Their car is parked outside.
• The students packed their bags.
• Their opinions matter to us.

In each case, their points back to the owner of whatever comes next. It never stands alone as a noun. It always attaches to something.

See More: Input Or Imput

Why Thier Feels Like It Should Be Correct

English spelling rules are full of exceptions, and the ie versus ei pattern is one of the messiest. The traditional rhyme goes:

I before E, except after C, or when sounded as “ay” as in neighbor and weigh.

Their does not fit neatly into that rhyme at all. It is not after a C, and it is not pronounced “ay.” That is exactly why so many people guess wrong and write thier instead. The word simply does not follow the pattern people expect, so the brain tries to “fix” it.

The honest answer is that their is one of English’s irregular spellings. It has to be memorized rather than sounded out through a rule.

Their Vs Thier Vs There Vs They’re: A Quick Comparison

Word	Part of Speech	Meaning	Example
Their	Possessive pronoun	Shows ownership	Their house is blue.
Thier	Not a word	Common misspelling of their	Incorrect in every context
There	Adverb / pronoun	Refers to a place, or introduces a sentence	Put the box over there.
They’re	Contraction	Short for “they are”	They’re coming to dinner.

These four words sound almost identical when spoken, which is exactly why they get mixed up so often in writing. Speech does not distinguish them. Only the spelling does.

How to Remember Their vs There vs They’re

A few simple memory tricks can make this permanent.

• Their contains the word “heir,” and an heir inherits ownership. Their is about ownership.
• There contains the word “here.” Both are about location or place.
• They’re has an apostrophe because it is short for two words: they are.

If you can replace the word with “they are” and the sentence still makes sense, you need they’re, not their or there.

• They’re going to the market. → They are going to the market. Correct.
• Their going to the market. → Their are going to the market. This does not work, so their is wrong here.

Grammar Breakdown: What Kind of Word Is Their?

Their is classified as a possessive determiner, sometimes grouped under possessive pronouns in simpler grammar guides. It always comes before a noun and modifies that noun by showing ownership.

Compare it with the possessive pronoun theirs, which stands alone.

• That is their car. (their + noun)
• That car is theirs. (theirs stands alone, no noun needed after it)

Their belongs to the same family as my, your, his, her, its, and our. All of these words answer the question “whose?” and all of them sit directly before a noun.

Singular They and Their

Their is also commonly used with a singular, gender-neutral meaning, especially when the subject’s gender is unknown or irrelevant.

• Someone left their umbrella at the office.
• Every employee should bring their badge tomorrow.

This is called the singular “they” or singular “their,” and it has been part of English usage for centuries, long before it became a modern style discussion. Major dictionaries and style guides recognize it as standard, everyday English.

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Common Mistakes With Their

Incorrect: Thier bags are on the table.
Correct: Their bags are on the table.

Incorrect: The dog wagged it’s tail near thier owner.
Correct: The dog wagged its tail near their owner.

Incorrect: Is it thier or their turn to present?
Correct: Is it their turn to present?

The fix is always the same. Swap the i and the e. Their, not thier.

A quick trick for catching this while proofreading: read your sentence slowly and look specifically at every “their,” “there,” and “they’re.” Spellcheckers often miss “their” versus “there” mix-ups because both are real words, but they will always catch thier, since it is not a word at all.

Their In A Sentence: More Examples

• The teachers reviewed their lesson plans before class.
• Birds build their nests in early spring.
• We respected their decision, even though we disagreed.
• Their flight was delayed by two hours.
• The company updated their return policy last month.

Notice that their always sits directly in front of a noun: bags, nests, decision, flight, policy. That placement is the clearest test for whether their is the word you need.

Pronunciation

Their is pronounced the same as there and they’re: “thair,” rhyming with hair, care, and fair. 

This shared pronunciation is the entire reason these three words get confused so often in writing, even by fluent, experienced writers. The ear cannot tell them apart. Only context and spelling can.

Origin Of Their

Their comes from Old Norse, from a word meaning “of them,” and it entered English through contact between Old English speakers and Norse-speaking settlers. Over time, it settled into the spelling we use today. 

This Norse origin is part of why their does not follow typical Old English or French-derived spelling patterns, and why it resists the usual “i before e” logic.

Their Or Thier In British English

The correct spelling is identical in both American and British English. There is no regional variation here. Their is standard across all major English-speaking countries, and thier is treated as a misspelling everywhere, not just in the United States.

See More: Nosey Or Nosy

Frequently Asked Questions

Is it thier or their? 

It is their. Thier is always incorrect, in every context and in every English-speaking country.

What does their mean? 

Their is a possessive word that shows something belongs to more than one person, or to a person whose gender is unspecified, as in the singular “their.”

Is their a noun or a pronoun? 

Their functions as a possessive pronoun, more specifically a possessive determiner, because it always comes before a noun.

How do you spell their correctly? 

T, H, E, I, R. The i comes before the e, which is the opposite order many people mistakenly use when they write thier.

What is the difference between their, there, and they’re? 

Their shows possession, there refers to a place, and they’re is a contraction of “they are.” All three sound identical but have completely different meanings.

Why do people spell their as thier? 

Because their does not follow the familiar “i before e, except after c” rule, writers often reverse the letters by habit, creating the common misspelling thier.

Can their be used for one person? 

Yes. Their is widely used as a singular, gender-neutral possessive, as in “Someone forgot their keys.”

Is thier a word in any dictionary? 

No. Thier does not appear as a valid entry in standard English dictionaries. It is only listed, if at all, as a common misspelling of their.

What is the plural of their? 

Their does not have a separate plural form. It already refers to more than one owner, or to a person whose number or gender is unspecified, without changing form.

Does their change in formal writing? 

No. Their is used exactly the same way in formal and informal writing. There is no more “correct” alternative spelling for formal contexts.

Final Thoughts

Their is the only correct spelling, and thier is simply a misspelling caused by a natural but mistaken assumption about English spelling rules. Once you remember that their relates to ownership, the same way “heir” does, the correct order of the letters becomes much easier to recall.

The best way to lock this in permanently is repetition and attention during proofreading. Every time you write a sentence about something belonging to more than one person, or to someone whose gender is unspecified, pause for a half second and check the spelling: their, not thier. With a little practice, it becomes automatic.