Sentences,Propositions and Predications 3)With the contrast between positive and negative (polarity),the circumstance described corresponds to some reality (a) or not (b). 4)Both 'the girl'and 'a horse'refer to something which exists.3) With the contrast between positive and negative (polarity), the circumstance described corresponds to some reality (a) or not (b). 4) Both ‘the girl’ and ‘a horse’ refer to something which exists. Sentences, Propositions and Predications