Interrogative

Development

In an imperative language, there would be some inappropriate imperatives - imperatives which could not be fulfilled, raising the specter of a breakdown in linguistic presence. In many cases, the one issuing the imperative would "let it go," either due to the unimportance of the request or the inability to enforce the command. However, a more complex situation could emerge - one where the imperative is not complied with, but it's not clear that it can't be complied with. The imperative is then repeated, first with more urgency, as a bluff by the imperator that he is able to enforce it; then with a degree of uncertainty, as he "climbs back down," but not completely. In this case, the imperative is prolonged, along with a tonal shift - becoming an interrogative.

References

Gans, E. L., Katz, A. L. (2019). The Origin of Language: A New Edition

Katz, A. (2020). Anthropomorphics.