English uses question words to ask about information. These words stand for the unknown part of the answer. They usually come at the beginning of a direct question. The main interrogative pronouns are who, what, which, and whose.

Word/Phrase	Definition
Who	Interrogative pronoun for asking about a person.
What	Interrogative pronoun for asking about a thing, idea, or event.
Which	Interrogative pronoun for asking about a choice from a known set.
Whose	Interrogative pronoun for asking about possession.

Who asks about the identity of a person or people. What asks about things, information, or actions. Use who for roles or names and what for objects or descriptions.

Word/Phrase	Definition
Who	Use to ask which person or people.
What	Use to ask for information, explanations, or things.

Which is used when the options are limited or clear to the speaker and listener. It selects from a set, not from everything possible. The set can be stated or understood from context.

Word/Phrase	Definition
Which	Use to ask for a choice from a defined group.

Whose asks about ownership or relationship to a possessor. It connects the question to a noun, such as book or car. The answer names a person or group as the owner.

Word/Phrase	Definition
Whose	Use to ask who something belongs to.

Where, when, why, and how are called interrogative words, but they are not pronouns because they do not replace a noun. They introduce questions about place, time, reason, and manner. They often appear with verbs like be, do, or have.

Word/Phrase	Definition
Where	Introduces a question about place.
When	Introduces a question about time.
Why	Introduces a question about reason.
How	Introduces a question about manner or method.

In English questions with interrogative pronouns, the question word comes first. It is followed by an auxiliary verb, then the subject, then the main verb. With be as the main verb, be comes before the subject in the question.

Rule
The question word comes first in a direct question.
In most questions, the auxiliary verb comes before the subject.
With be, place be before the subject to form a question.

Interrogative pronouns in English are who, what, which, and whose. They introduce questions by standing for the unknown information. Correct use depends on whether you are asking about people, things, choices, or possession.