The assessment of an imperative in terms of cost-benefit of the imperative proposition for the speaker or addressee has been considered an important factor determining the illocutionary force of an imperative and the associated speech act and politeness values. However, this factor has so far been operationalized only vaguely, based on the individual researcher's perception of the extralinguistic conditions of the speech situation. In this paper, we report an experimental study on Czech that demonstrates a way of rigorous operationalization of the speaker’s/addressee’s benefit through manipulating the linguistic context preceding an imperative in terms of the grammatical person of a modal verb expressing a rationale for the imperative. We found that the preceding modal verb in the first person prompts the assessment of an imperative as benefiting the speaker, while a second person modal prompts the interpretation as benefiting the addressee, all other utterance parts kept constant. This effect was more pronounced in singular than in plural imperatives, which we explain by the inclusive interpretation of the first-person plural not allowing for distinguishing between speaker vs addressee benefit.
Chromá et al. (Wed,) studied this question.