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WHO'S / WHOSE
Who's is short for who is or who has. (This is a 100% rule - it has no other
uses.)
Whose sits before a noun to state (or ask) to whom it belongs (e.g.,
A king whose crown is too big. Whose crown is this?)
The terms whose and who's
sound identical, but they perform very different roles in English.
Whose
Whose is the possessive form of who. It means
'belonging to whom'. Whose usually sits before a
noun.
Whose bike was expensive?
(bike - noun)
("Whose" in this example is an interrogative
pronoun.)
Carl knows the girl whose phone was stolen.
(phone - noun)
("Whose" in this example is a relative
pronoun.)
Who's
Who's is a contraction of either
who is or who has. It has no other uses.
Who's coming to fix the bed?
(who is)
Who's eaten the last muffin?
(who has)
I met the inspector who's delivering tomorrow's briefing.
(who is)
Select the correct version:
WHO'S = WHO IS OR WHO HAS
If you cannot substitute the who's in your sentence with either
who is or who has, then it is wrong.
Easily Confused Words
Whose bike was expensive? 
