whom vs. whose

[Nathan Smith]

Will someone be so kind to show me the difference between whose and whom?

[Cerberus™]

Whom is used when it is the object of the finite verb in the subordinate clause: The man whom I killed was my father: "whom I killed" is the subordinate clause, and "whom" is the object of "killed": who was it that I killed? => the man. You could replace the whole sentence with: I killed a man; he was my father.

Whose is used when it is the possessive in the subordinate clause: The man whose wife I killed was my father: "whose wife I killed" is the subordinate clause, and "whose" is a possessive belonging to "wife: I killed the wife of which person? => the man. You could replace the whole sentence with: I killed a man's wife; he was my father.