This paper suggests that wh-arguments such as ``who`` and ``what`` are DP-arguments, whereas a wh-adjunct ``why`` is an NP-adverbial (introduced by a null preposition). Under this proposal, it will be claimed that wh-arguments can check the u[Wh] within the DP without movement due to the presence of the head D bearing the [Q], whereas a wh-adjunct ``why`` must move to check its u[Wh] due to lack of the D. This claim will be illustrated by the asymmetry arising between wh-arguments and wh-adjunct ``why`` in the Islands in Korean/Japanese, supporting that the Phase Impenetrability Condition constrains covert wh-movement as well as overt wh-movement.

Ki-Yang. Kwon. 1998. Free-Rider and Independent Feature Checking. Studies in Modern Grammar 14, 47-61. In this paper, we will suggest that it is not required that when the operation move-F affects a FF, all FFs associated with F move to the target as free riders. Rather, we will assume that only the necessary formal feature of the moved element individually enters into a checking relation with the target that has matching features for a local convergence of derivation, and that the feature checking may hold between individual formal features that have matching features that can enter into checking relations. This suggestion is based on the inverse voice constructions in Bantu, there-construction involving wh-movement and the conjunct associate, and inalienable possession constructions of Japanese.