The following is a mini-tutorial on the uses of "who," "whom," and "whose." If you already know how to use these words, you can skip the explanation and go directly to the exercises.
To understand how to use "who," "whom," and "whose," you first have to understand the difference between subjects, objects, and possessive forms.
Subjects do an action:
Objects receive an action:
Possessive forms tell us the person something belongs to:
"Who" is a subject pronoun like "he," "she" and "we" in the examples above. We use "who" to ask which person does an action or which person is a certain way.
"Whom" is an object pronoun like "him," "her" and "us." We use "whom" to ask which person receives an action.
"Whose" is a possessive pronoun like "his," "her" and "our." We use "whose" to find out which person something belongs to.
The sentence below contains an example of an indirect question:
Such sentences usually start with a phrase such as: "I am not sure" or "He doesn't know" or "We don't care." Just ignore the first part of the sentence and look at the indirect question when deciding whether to use "who," "whom" or "whose." Ask yourself if the indirect question requires a subject, object, or possessive form.
The sentence below contains an example of an adjective clause:
Adjective clauses are used to describe a noun in the main sentence. In the example above, the adjective clause tells us about "the man." Just ignore the main sentence and look at the adjective clause when deciding whether to use "who," "whom" or "whose." Ask yourself if the adjective clause requires a subject, object, or possessive form.
The form "whom" is becoming less and less common in English. Many native English speakers think "whom" sounds outdated or strange. This trend is particularly common in the United States. Especially when combined with prepositions, most people prefer to use "who" as the object pronoun. To most native English speakers, the examples below sound quite natural.