6 Phrasal typology and the interaction of topicalization, wh-movement, and extraposition Tibor Kiss 6.1 Introduction Ever since Chomsky’s “On Wh-Movement” (Chomsky 1977) it has been assumed that topicalization and wh-question formation can be analyzed as instances of the same operation. Leaving certain features aside, this proposal carries over to the analysis of unbounded dependency con- structions in HPSG since structurally, topicalization does not differ from wh-question formation in the analysis suggested in Pollard & Sag (1994:157-163). 1 In the present paper, we challenge this assumption and suggest an alternative analysis of unbounded dependency construc- tions. Here, topicalization and wh-question formation are considered as structurally different at least in certain languages. They may, however, be structurally identical in other languages. This difference is empiri- cally reflected in patterns of relative clause extraposition. As has been pointed out by Culicover & Rochemont (1990:28), an extraposed rela- tive clause must not take an antecedent contained in a VP if the VP is topicalized but the relative clause is not. 2 1 It must be made explicit, though, that Pollard/Sag (1994) assume that these operations involve different combinations of attributes of the sign. Moreover, Pol- lard/Sag (1994) illustrate unbounded dependency constructions with topicalization cases and leave a detailed analysis of wh-question formation open. It is still a tacit assumption of this work that both wh-question formation and topicalization are syntactically realized through the Head-Filler Schema (Pollard/Sag 1994:164). 2 Example (2) could be grammatical if the relative clause would take the subject as its antecedent. This is problematic, however, since the antecedent is a pronoun. The Proceedings of the 9th International Conference on HPSG. Jong-Bok Kim and Stephen Wechsler. Copyright c  2003, Stanford University. 109