qui, què, on

Qui truca? asks who is calling. Què vols? asks what you want. On vius? asks where you live. A question word fills a role in the sentence; it does not require an extra English-style do auxiliary.

Keep the accent on interrogative què, including in indirect questions: no sé què vol. Relative que, which connects a noun to a description, has no accent. Qui and on do not take an accent simply because they introduce a question.

A preposition can come before the question word: amb qui parles?, de què parleu?, d'on vens? Put it with the word at the beginning rather than leaving it at the end as English sometimes does. The preposition reflects the verb or the intended relationship.