“Who’s” and “whose” sound exactly alike, which is exactly why they get swapped so often — but the apostrophe makes all the difference.
The Short Answer
Who’s is a contraction of “who is” or “who has.” Whose is a possessive pronoun showing ownership. If you can expand the word to “who is” or “who has” and the sentence still makes sense, use “who’s.” Otherwise, use “whose.”
Examples of “Who’s”
- Who’s coming to the party tonight?
- Do you know who’s responsible for this?
- Who’s been eating my sandwich?
- Who’s ready for the meeting?
Examples of “Whose”
- Whose jacket is this?
- I don’t know whose car is parked outside.
- The author, whose book just won an award, spoke at the event.
- Whose turn is it next?
The Expansion Test
Try substituting “who is” or “who has” into the sentence. “Who’s coming?” becomes “Who is coming?” — that works, so “who’s” is correct. “Whose jacket is this?” would become “Who is jacket is this?” — that doesn’t make sense, so “whose” is the right choice.
Why This Pair Is So Often Mixed Up
English has several possessive/contraction pairs that sound identical but are spelled differently (its/it’s, your/you’re), and “who’s” vs. “whose” follows the exact same pattern. Because the apostrophe carries no sound difference in speech, the mix-up shows up almost exclusively in writing, not conversation.
Frequently Asked Questions
How do I know which one to use?
A: Try expanding it to “who is” or “who has” — if that makes sense, use “who’s”; if not, use “whose.”
Is “whose” only used for people?
A: No — “whose” can also refer to objects or ideas, as in “the company whose policy changed,” even though it originated as a possessive form of “who.”
Is this the same pattern as “its” and “it’s”?
A: Yes — both pairs follow the same rule: the apostrophe version is always a contraction, and the non-apostrophe version shows possession.
