On the nature of the epistemic readings of the Italian modal verbs: the relationship between propositionality and inferential discourse relations

The present contribution deals with the epistemic readings of the Italian modal verbs dovere ('must') and potere ('may'/'can'). The two verbs show striking differences — both quantitative and qualitative — with respect to the possibility of epistemic interpretation, differences which have gone so far completely unnoticed in the — rather scarce — semantic literature on modal verbs in Italian. Even a cursory examination of corpus data shows that, contrary to standard assumptions, the occurrences of potere that are unambiguously to be interpreted epistemically, are much rarer than the epistemic/evidential readings of dovere, and, at least in the spoken language, tend to be limited to one particular syntactic pattern. A careful examination of the data shows that the epistemic readings of the two verbs differ systematically along two semantic dimensions: (1) The presence of an inferential evidential meaning and — consequently— the ability to function as trigger for the establishment of an inferential discourse relation between two discourse units (evidentiality). (2) The belonging of the modal predicate to the propositional (or truth-conditional) part of the meaning of an utterance or to the non propositional (non truth-conditional) part (propositionality). These observations, together with a reconsideration of the relationship between epistemic modality and deixis, lead us to conclude that the (so-called) "epistemic" interpretations of the verbs potere and dovere belong, in fact, to two semantically distinct kinds of modality and to hypothesise that they arise from different pragmatic processes.