Predication vs. aboutness in copy raising

Copy raising sentences (Charlie looks like his prospects are bright) are ambiguous between a thematic and a nonthematic reading for the subject, corresponding to whether or not it is the perceptual source. On the basis of Hebrew and English data, this paper motivates a novel generalization: a pronominal copy in the complement is necessary if and only if the matrix subject is not thematic. This follows if (i) a nonthematic DP must be licensed by predication, (ii) the clausal complement is turned into a predicate by merging with a null operator, and (iii) the pronominal copy is the variable required by the operator. Contra previous analyses, I argue that the complement in copy raising may be propositional, forming an aboutness relation with the subject. When it is predicative, however, a null operator is necessary, since CPs are not natural predicates. The dichotomy between propositional and predicative CPs cuts across the gap/copy distinction, and is manifested in other constructions, also discussed (hanging topic vs. left dislocation, rationale vs. purpose clauses, and proleptic object constructions).