On the Distribution of Complementizers in How come Interrogatives

This paper aims to investigate the syntactic structure of how come interrogatives. In particular, I focus on two interesting aspects where how come differs from other wh-interrogatives; 1) how come interrogatives do not show T-to-C movement, and 2) while C should remain null, it must be overtly realized when modifiers intervene between how come and the rest of the clause. To resolve the puzzles, I assume that how come externally merges to a relatively higher position than other wh-phrases. Thus, unlike other root wh-interrogatives where C values an uninterpretable clause-type feature on T, how come values the [uclause-type: ] feature on T instead, which prohibits T from undergoing movement to C. I also assume that C is split into Foc and Fin (Rizzi 1997), and a modifier head may intervene between the two heads (Rizzi and Shlonsky 2007). I argue that [uwh] and [Q] in root wh-interrogatives originate from separate heads – Foc and Fin, respectively – and morphological affixation takes place via Fin-to-Foc movement. If the head movement is prohibited by an intervening modifier head, Fin[Q] must be overtly realized with overt complementizer that.