Who's is short for who is or who has. (This is a 100% rule - it has no other
Whose is a bit more complicated. It sits before a noun to state (or ask) to whom it belongs. For example:
Who's and WhoseThe terms whose and who's sound identical, but they perform very different roles in English.
WhoseWhose is the possessive form of who. It means belonging to whom. Whose usually sits before a noun.
Conscience is a mother-in-law whose visit never ends.
(Whose is before the noun visit. Whose in this example is a relative pronoun.)
Whose bike was expensive?
(Whose is before the noun bike. Whose in this example is an interrogative pronoun.)
Carl knows the girl whose phone was stolen.
(Whose is before the noun phone. Whose in this example is a relative pronoun.)
Who'sWho's is a contraction of either who is or who has. It has no other uses.
Who's coming to fix the bed?
Who's eaten the last muffin?
I met the inspector who's delivering tomorrow's briefing.
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.