Previous research has shown that usage preferences (non-categorical constraints on the distribution of syntactic structures) shape many grammatical alternations. In the present study, we show that usage preferences also influence which alternate listeners report hearing when presented with acoustically degraded input. We investigated the English expletive/null subject alternation in sentences such as "(It) seems like things are going well." We hypothesized that this alternation is shaped by pragmatic constraints: sentences with null (zero) subjects tend to express immediate judgments, i.e., judgments that the speaker has just formed at utterance time. A corpus study supported this hypothesis, revealing that the relative frequency of zero sentences is higher in temporally immediate (i.e., present tense) sentences than in non-immediate (i.e., past tense) sentences. A speech restoration experiment demonstrated that listeners are sensitive to this constraint. In that study, participants listened to short dialogues that varied with respect to immediacy, concluding with a sentence with an acoustically distorted expletive subject. Participants reported hearing zero sentences more often in immediate contexts. The results suggest that usage preferences influence what listeners think they are processing. (Contains 8 tables.)