This paper is concerned with wh-interrogative clauses in which the imperative verbal mood occurs. According to some authors (cf. in particular Lohnstein, 2000; Chiba, 2009), such constructions are ill-formed. Lohnstein offers a semantic account (based on his theory of sentence mood) ruling out imperative (wh-)interrogatives by arguing for the impossibility of partitioning propositions which are not open for truth value assignment. Chiba argues for the ungrammaticality of such structures by assuming that sentence types (as defined by Sadock & Zwicky, 1985) cannot be combined. This paper will show that unacceptable as well as acceptable imperative wh-interrogatives exist and that, therefore, both approaches make the wrong predictions. A pragmatic approach is developed which argues for the realization of incompatible illocutionary acts. This account makes it possible to derive the unacceptability of certain imperative wh-interrogatives and to allow the acceptable cases which can be observed. An advantage of referring to illocutionary acts is that it becomes possible to speak about various subtypes of the erothetic illocution which can be proven to play a role in distinguishing between acceptable and unacceptable imperative wh-interrogatives. The results of controlled acceptability judgements confirm this assumption.
In Müller (2013), I argue that there is a further option to solve this conflict with present subjunctive wh-interrogatives. The shift can also concern whether the verbal mood is attributed to the questioner or to the addressee.