The interrogatives (pronouns and adverbs, 340, cross346) are used in direct and in indirect questions. In indirect questions
the indefinite relatives ὅστις, etc., are generally used instead of the interrogatives.
τί βούλεται ἡμῖν χρῆσθαι;
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].