Properties of ought-to-be deontic modal

In this article, we discuss different concepts of obligation based on the distinction originally established by Feldman (1986): (i) ought-to-be interpretation, which involves a property that a certain state of affairs must occur; and (ii) ought-to-do interpretation, which relates an agent to a state of affairs. We assume this conceptual distinction results from structural differences. In this line of argumentation, we follow authors like Brennan (1993) and Hacquard (2006, 2010). Since there is not yet a proposal of structural representation in the literature that contemplates the ought-to-be interpretation, we searched for evidence in Brazilian Portuguese to ascertain more precisely the position at which this deontic is structurally merged in order to generate its interpretation. We scrutinized factors such as the deontic's orientation, its relation to other modal heads and also to tense and aspect categories. Our tests confirmed the existence of a high deontic (ought-to-be). This modal displays the properties of a directive speech act, being oriented towards an agent in the speech situation (usually the addressee), and it does not bear aspect or tense markers. Even though ought-to-be deontics do not share all these properties with the epistemics, there is evidence that they occupy the same position in the structure. Lastly, we also suggested that ought-to-be, ought-to-do deontics and epistemics can be distinguished based on two features: agentivity [Ag] and assertion [Assert].