Its or it's, your or you're, whose or who's are among the most common apostrophe errors in English, and a spell-checker accepts both spellings because each is a real word. One rule settles all five. Definitions here draw on Wiktionary via kaikki.org, a structured export of over 1,000,000 English dictionary entries; see our methodology.
The one rule
A possessive pronoun never takes an apostrophe, its, your, their, whose and theirs show ownership with no apostrophe, so any apostrophe form (it's, you're, who's) is a contraction you can expand back into two words.
- 5
- confusable pairs settled
- 1
- rule covers them all
- Never
- an apostrophe on a possessive pronoun
According to Wiktionary variant data (CC BY-SA, May 2026). Below: the five pairs side by side, the expand-it test, and why the noun rule misleads you.
How similar each pair looks (letters only, ignoring the apostrophe)
More similar = harder to distinguish at a glance
- its / it's
its / it's
100 % match
- their / they're
their / they're
83 % match
- your / you're
your / you're
80 % match
- whose / who's
whose / who's
80 % match
- theirs / there's
theirs / there's
67 % match
What this shows Its and it's are letter-for-letter identical when you ignore the apostrophe, the riskiest pair. Theirs and there's differ by two letter positions, making it the easiest in this set to catch.
The Five Apostrophe Pairs
The possessive form (no apostrophe) shows ownership; the apostrophe form is always a contraction. Read each example aloud and the difference is obvious.
| Possessive (no apostrophe) | Contraction | Stands for | Example |
|---|---|---|---|
| its | it's | it is / it has | It's raining, and the cat licked its paw. |
| your | you're | you are | You're early, is this your seat? |
| their | they're | they are | They're bringing their dog over there. |
| whose | who's | who is / who has | Who's the writer whose book won? |
| theirs | there's | there is / there has | There's a seat free; the corner one is theirs. |
The "Expand It" Test
Whenever you reach for an apostrophe form, expand it into the two words it stands for and re-read the sentence. If the longer version makes sense, the apostrophe is correct. If it sounds wrong, you need the possessive instead.
"The company lost its licence" expands to "the company lost it is licence", which is nonsense, so the possessive its is right. "It's been a long week" expands to "it has been a long week", which is fine, so the contraction it's is right. The same test settles your/you're and who's/whose.
Why the Noun Rule Misleads You
For ordinary nouns, possession is marked with apostrophe-s: the dog's bowl, Sarah's car, the company's profits. Writers carry that habit over to pronouns and add an apostrophe to show possession, but pronouns already have their own possessive forms built in: its, your, their, whose, theirs, his, hers and ours. None of them uses an apostrophe. So on a pronoun, an apostrophe is reserved entirely for contractions, which is the exact reverse of the noun rule and the reason these five pairs trip up so many writers.
Frequently Asked Questions
What is the difference between its and it's?
"Its" (no apostrophe) is the possessive: the dog wagged its tail. "It's" (with an apostrophe) is the contraction of "it is" or "it has": it's raining. The test: read the sentence with "it is" - if it still makes sense, write it's; otherwise write its.
Your or you're?
"Your" is the possessive (your book, your idea). "You're" is the contraction of "you are" (you're right). If you can replace the word with "you are", use you're; if not, use your.
When do possessive pronouns take an apostrophe?
Never. Its, yours, his, hers, ours, theirs and whose are possessive pronouns and none of them uses an apostrophe. The apostrophe-plus-s on these words always signals a contraction (it's = it is, who's = who is), never possession.
Whose vs who's?
"Whose" asks or states possession: whose coat is this? "Who's" is the contraction of "who is" or "who has": who's coming? Replace it with "who is" to check.
Why is this confusing when other possessives use an apostrophe?
For nouns, the possessive does take an apostrophe (the dog's tail). But pronouns have their own dedicated possessive forms, its, your, their, whose, that never use one. So with a pronoun, an apostrophe always means a contraction, the opposite of the noun rule.
What to do with this
One test settles every one of these five pairs, no memorising required.
- Reaching for an apostrophe form? Expand it into the two words it stands for; if the sentence breaks, you need the possessive instead. See "its"
- These are same-sound, different-spelling traps, the wider set of confusable pairs works the same way. Confusable pairs
- Homophones cause the same spell-checker blind spot across English, where both spellings are real words. Homophones guide
A spell-checker accepts both spellings because each is a real word, only meaning tells them apart.
