Who’s or whose? The difference between these homophones is simple:
- Who’s is a contraction of who is or who has.
- Whose is the possessive form of who or which.
Think of it this way: If you were to replace who’s/whose with who is, would it mean the same thing? If yes, you want who’s. If no, you want whose.
Some examples of correct whose/who’s usage:
Celebrity birthdays: Who’s another year older Jan. 11? [OC Register]
Who’s Renting What on Netflix? [World's Strangest]
Whose ass should I kick at ping-pong? [Warming Glow]
I am convinced this really is an idea whose time has come. [FDL]
Whose and inanimate objects
As in that last example above, whose—unlike who or who’s—may apply to inanimate objects or other non-person entities. For example, while you wouldn’t say, “The book, who is 500 pages, was released in 1923,” you could say, “The book, whose 500 pages fly by, was released in 1923.” This usage arises out of the fact that there is no equivalent word in English that’s strictly for inanimate objects.
