EN
The subject of the paper are such types of utterances as Nie sądzę, że p, ja to wiem (I don t believe that p, I know it). In particular, interpretive controversies of this kind of utterances are discussed. The applied research method consists in a comparative analysis of the collected language material. Moreover, the present-ed extensive empirical material confirms the thesis that such utterances are indeed corrective. The conclu-sions from the analyses support the thesis that the classical definition of knowledge (of justified true belief) is internally contradictory due to the fact that verb wiedzieć, że_ (know that_) is defined by a non-factive verb być przekonanym, że_ (be convinced that_).