Testing Factivity in Italian : Experimental evidence for the hypothesis that Italian sapere is ambiguous
In linguistics and in the philosophy of language it is standardly assumed that know is a factive verb, meaning that a sentence such as X knows that p, when uttered in its positive declarative form, presupposes, in fact entails, the truth of its complement. A problem for this analysis is the fact that the verb know can be used non-factively in contexts where it is evident that the proposition expre