when i have to use who-whom-whose
When do I use who? - who is used as the subject of a verb. Who is it? Who went to bed last?
Originally Posted by Unregistered
When do I use whom? - whom is used as the object of a verb. To whom am I speaking? This belongs to whom?
When do I use whose? = whose is a possessive determiner = belonging to or associated with which person. Whose is this pen? Whose coat is on the floor?
However, it is now very common to use "who" instead of "whom".