Interrogative pronouns are used in questions. How much is used with uncountable nouns, whilst How many is used with countable nouns.

Interrogative pronouns Rule Examples
Who? (Chi?) It is used in questions as subject.
  • Who wrote this sentence?
Whom? (Chi?) It is used in questions as object or complement
  • Whom did you write that letter to?
What? (Che cosa? Quale/Quali) It is used in general questions.
  • What are you going to do if you fail your exam?
Whose (Di chi?) It is used in questions to express possession. It is immediately followed by the thing owned.
  • Whose socks are these?
  • Whose dog is it?
Which? (Quale/i?) It is used in questions to express a choice among a small number of options.
  • Which colour do you like best? Black or blue?
  • Which line shall I take? The green line or the red one?
How much? (Quanto/a?) It is used only with singular uncountable nouns
  • You must drink one litre of water per day. How much, did you say?
How many? (Quanti/e) It is used with plural countable nouns
  • Yesterday I bought 4 book. How many, did you say?
Interrogative pronouns