Interrogative personal pronouns
wie? | who?
wat? | what?
wat voor? | what kind of?
welk(e)? \* | which?
(\*) We use _welk_ before het-nouns, _welke_ before de-nouns and plural nouns. If not followed by a noun, _welke_ is used. See also [interrogative pronouns](#/lesson/Pronouns.It01).
Interrogative possessive pronouns
wiens? | whose? (singular AND male)
wier?\* | whose? (plural AND/OR female)
(\*) Most people use the singular male form - _wiens_ \- even when referring to females. If used at all, it is used as a relative pronoun, hardly ever as an interrogative pronoun.
Interrogative adverbs
waar? | where?
wanneer? | when?
hoe? | how?
Interrogative number
hoeveel? | how much?
Interrogative adverb-prepositions
waarmee? | with what?
waarom? | why?
waardoor? | due to what?
waaronder? | under what?
waarachter? | behind what?
waarlangs? | along what?
The category of interrogative adverb-prepositions is far from complete. The word 'wat' is not used in combination with a preposition.\* Instead, we use _waar_. Moreover, we place _waar_ before the preposition and attach it to it. You can compare it with [het turning into er](#/lesson/WordOrder.09).
(\*) An exception to this rule is _wat voor_, meaning 'what kind of'.