"Who" is a subject pronoun like "he," "she" and "we" in the examples
Examples:
"Whom" is an object pronoun like "him," "her" and "us." We use "whom" to ask which person receives an action.
Examples:
"Whose" is a possessive pronoun like "his," "her" and "our." We use "whose" to find out which person something belongs to.
Examples: