Constraints on relative clause extraposition 
in English

In this paper, I present a psycholinguistic experiment on relative clause extraposition in English. In the theoretical literature, it has frequently been claimed that the acceptability of relative clause extraposition decreases when the antecedent NP of the relative clause is definite (the definiteness restriction) and when the main verb of the sentence is not a verb of appearance (the predicate restriction). However, the literature also contains conflicting judgments, suggesting the need to test the acceptability of relative clause extraposition experimentally. Using the method of thermometer judgments (Featherston 2007) to elicit acceptability judgments, I provide evidence that objectively and reliably corroborates the definiteness restriction and the predicate restriction. Additionally, I show that the grammatical function of the antecedent NP has an effect on the acceptability of relative clause extraposition only when verbs other than verbs of appearance are used in the sentence.