Here's a breakdown of how these two parts of speech work:
* Nouns: Examples include: *cat, house, happiness, London, John, book*
* Interrogative words: These include: *who, what, where, when, why, which, how*
Interrogative words can be used to ask questions about nouns:
* Who is going to the party? (Asking about a person)
* What is your favorite color? (Asking about a thing)
* Where did you find that book? (Asking about a place)
* When will you be back? (Asking about a time)
* Why did you choose that? (Asking about a reason)
Interrogative words are not nouns. They are a separate part of speech used to create questions.