Don’t panic. “Whose” and “who’s” are much easier to differentiate than “who” and “whom.”.
The short version
Whose is the possessive form of “who.” It is used to show ownership.
Who’s is a contraction, a shortened version of “who is,” or “who has.” This is the ONLY THING “who’s” can mean.
If you’re debating which one to use, substitute “who is” or “who has” in place of who’s/whose. If the sentence retains its meaning, the “who’s” is the correct form.
If the sentence loses its meaning, then “whose” is the correct form.
The long version is a little, well, longer. But not by much.
When to use Whose
Whose is the possessive form of “who.” Normally, possession is shown by an apostrophe “s,” but not with this form. The good news is that this function is the only role “whose” can play in a sentence.
Stacy, whose mother works at the café downtown, is learning to bake cinnamon rolls to sell there.
Whose shoes were left by the door?
I don’t care whose fault it was, we can’t let a mistake like this happen again.
In each of these sentences, “whose” fails the “who is/has” substitution test. In sentence 1, “whose” shows Stacy’s possession of her mother. In sentence 2, “whose” concerns the owner of the shoes left by the door. In sentence 3, “whose” concerns who should get the blame for the mistake.
When to use Who’s
With who’s, you can simply spell out the contraction to see if it’s correct.
Do you know who’s going to the show tonight?
In his high school yearbook, Leslie was voted “Most Popular” on the yearbook’s Who’s Who page.
Jamie, who’s gone to the store, should return in just a few minutes.
Each of these sentences still makes perfect sense when you replace “who’s” with “who is” or “who has.”
Breathe a sigh of relief. You’ve got “who’s” in the bag.
Check your understanding with these sentences.
Kyle, (who’s, whose) going to New York in the fall, loves architecture.
I found this takeout box in the fridge at work. Do you know (who’s, whose) it is?
John felt safe around Kelly, (who’s, whose) taken many self-defense classes.
Mark composed a list of (who’s, whose) attending the cooking class at the community center.
Of all the bankers at the conference, (who’s, whose) had more experience than Derrick?
Anyone (who’s, whose) had experience in graphic design can help me with my project.
Chicago, a city (who’s, whose) architecture is admired all over the world, has a population of over 2 million residents.
(Who’s, Whose) yellow car is parked in front of your house?
William Faulkner, (who’s, whose) books I read in high school, remains one of my favorite authors.
(Who’s, Whose) idea was it to eat dinner here? The service is terrible.
Answers: 1. who’s, 2. whose, 3. who’s, 4. who’s, 5. who’s, 6. who’s, 7. whose, 8. whose, 9. whose, 10. whose