The main wh- pronouns are: what, which, who (whom) and whose. The wh- adverbs are: how, why, when, and where.
- They can be used as relatives.
- They can be used as interrogatives.
- The pronouns whose, what and which can be used as determiners
There are also some archaic question words:
- whence (from what place; from what source)
- wherefore (what for; why)
- whither (to what place; where)