The syntax of Why-Stripping
This study investigates a clausal ellipsis construction involving the adverbial wh-phrase why and a non-wh-remnant, hereafter Why-Stripping. We show that Why-Stripping exhibits movement properties such as connectivity effects in the same way as Sluicing (with argument wh-phrases) and Stripping, and claim that Why-Stripping involves movement of the focused phrase (e.g. Mary) followed by clausal ellipsis. Furthermore, based on the fact that Why-Stripping does not show strict locality restrictions, unlike Sluicing with why, we claim that why in Why-Stripping is base-generated in the Spec_CP position while Sluicing with why involves adjunct wh-movement. According to this view, there are two types of why: one that moves and the other that does not move. It is shown that the latter induces focus association and participates in Why-Stripping. Thus, the investigation of Why-Stripping contributes to revealing the nature of the syntax of why itself.
stripping ellipsis why connectivity effects sluicing how come