The island status of clausal complements: Evidence in favor of an information structure explanation

The present paper provides evidence that suggests that speakers determine which constructions can be combined, at least in part, on the basis of the compatibility of the information structure properties of the constructions involved. The relative "island" status of the following sentence complement constructions are investigated: "bridge" verb complements, manner-of-speaking verb complements and factive verb complements. Questionnaire data is reported that demonstrates a strong correlation between acceptability judgments and a negation test used to operationalize the notion of "backgroundedness". Semantic similarity of the main verbs involved to think or say (the two verbs that are found most frequently in long-distance extraction from complement clauses) did not account for any variance; this finding undermines an account which might predict acceptability by analogy to a fixed formula involving think or say. While the standard subjacency account also does not predict the results, the findings strongly support the idea that constructions act as islands to wh-extraction to the degree that they are backgrounded in discourse.