Whereas a factive verb presupposes the truth of its complement, whether the verb is negated or not, a paradigm counterfactive verb would presuppose the falsity of its complement, whether negated or not. R. argues that, though some verbs presuppose the falsity of their complement if used in an affirmative sentence (e.g. 'pretend' in 'John is pretending that he forgot to send that telegram', such paradigm counterfactives cannot exist.