Necessity, directives, and three types of imperatives

In Japanese, dictionary (i.e. end) form sentences and yooni form sentences can represent ‘directive’ (or ‘command’) speech acts, just like the typical imperative form imperatives. This study investigates properties of three types of imperatives in Japanese: Morphological Imperatives (MIs), Dictionary form Imperatives (DIs), and Yooni Imperatives (YIs). What is the difference among MIs, DIs, and YIs? Specifically, (i) how do they semantically differ from one another? and (ii) what makes the difference among these three imperatives? I argue that the difference depends on whether they encode a weak necessity modal (Silk 2013, 2016) and a directive presupposition operator (Kaufmann 2012) or not.