Bunlar kimin kitapları? - Whose books are these?
Bunlar kimin kitapları?
Whose books are these?
Tom'u kovmak kimin fikriydi. - Whose idea was it to fire Tom?
Tom'u kovmak kimin fikriydi.
Whose idea was it to fire Tom?
This is the man whose dog caused the accident. (=This man's dog caused the accident.).