A pronoun is a word that substitutes for a noun or a noun phrase. Pronouns are classified into 6 types: personal pronouns; demonstrative pronouns; indefinite pronouns; relative pronouns; interrogative pronouns; and reflexive and intensive pronouns.
Interrogative pronouns are used to ask questions. These are the most common interrogative pronouns:
- who
- whom
- whose
- which
- what
The interrogative pronouns "whoever," "whomever," "whichever," and "whatever" are less commonly used.
Note that "who," "whom," and "which" can also be used as relative pronouns.
Also note that the interrogative adjectives "which" and "what" are identical to the interrogative pronouns "which" and "what." The part of speech of each word is determined by its function in the sentence.
- What are you reading? [The interrogative pronoun "what" is the subject of the sentence.]
- What book are you reading? [The interrogative adjective "what" modifies the noun "book."]
