Sometimes possession doesn���t require an apostrophe. Such is the case with these two often confused words.
Who���s is a contraction for who is, and less commonly who has. For example, Who���s bringing potato chips to the party?
Whose is the possessive form of who, showing that something belongs to who. To wit, Whose house is the party at? (You wouldn���t write Who is house is the party at?...)
While an apostrophe typically is used to show possession, of course it also can be used to show a contraction. The latter is the case with who���s. And while rare, sometimes possession is shown by changing the form of the word, as in whose.
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