The difference in the morphological and semantic properties of cross-linguistic wh-expressions is due to the difference in wh-question formation strategies. It is the contention of this paper that wh-expressions are universally consistent, in the sense that their semantic force is undetermined in the lexicon. However, once they are chosen for the computation, the wh-expression becomes merged syntactically with another element and this gives rise to relative or interrogative semantic interpretation. The syntax of wh-expression generally falls in two categories: argument wh-expression and non-argument wh-expression. In conclusion, this paper maintains that the wh-movement's driving force is underspecified by the [+Q] feature of the head C operator wherein the interpretation that wh-expression gets is at the level of the interface.