The difference between WHO'S and WHOSE

WHO'S is a contraction of who is or who has. It is used in questions and in statements, as shown in the examples below.

• Who’s this? [who is]
• Who's in charge here? [who is]
• She is a good student who's always been interested in math [who has]
• Who’s got my keys? [who has]

WHOSE has two different uses. It can be placed in front of a noun, to ask or show who the owner of something is, as in these examples:

• Whose bag is it?
• The gentleman whose cell phone was stolen was very upset.
• My roommate, whose sister is an actress, gets lots of requests for autographs.

WHOSE can also be used in front of a verb, to represent a noun that is not included in the sentence but is understood from the context. It must already be clear to the listener what noun the speaker is referring to.

• Whose are these?
• Let him know whose you will choose.