Online comprehension of conditionals in context: A self-paced reading study on wenn ('if') versus nur wenn ('only if') in German

Comprehending conditional statements is fundamental for hypothetical reasoning about situations. However, the online comprehension of conditional statements containing different conditional connectives is still debated. We report two self-paced reading experiments on German conditionals presenting the conditional connectives wenn ('if') and nur wenn ('only if') in identical discourse contexts. In Experiment 1, participants read a conditional sentence followed by the confirmed antecedent p and the confirmed or negated consequent q. The final, critical sentence was presented word by word and contained a positive or negative quantifier (ein/kein 'one/no'). Reading times of the two quantifiers did not differ between the two conditional connectives. In Experiment 2, presenting a negated antecedent, reading times for the critical positive quantifier (ein) did not differ between conditional connectives, while reading times for the negative quantifier (kein) were shorter for nur wenn than for wenn. The results show that comprehenders form distinct predictions about discourse continuations due to differences in the lexical semantics of the tested conditional connectives, shedding light on the role of conditional connectives in the online interpretation of conditionals in general.