Order in phrase structure and movement

This article proposes the following mechanism of Merge, modifying and incorporating the effect of the head parameter: K = {gamma, [alpha, beta]}, where gamma is an element of {a, beta} a. gamma = alpha: head-initial, left-headed b. gamma = beta: head-final, right-headed It is argued that under the parameterized version of Merge, traditional "adjunction" operations (scrambling and heavy NP shift) are characterized as substitution in the sense that they always accompany the projection of the target, whereas traditional "substitution" operations (wh-movement and NP-movement) are analyzed as genuine adjunction. It is then shown that numerous empirical consequences follow from this theory of phrase structure and movement, including (a) the nature and distribution of optional movements, (b) an elegant account of some peculiar properties of specifiers, and (c) a new unification of adjunct and subject condition effects, with a natural explanation of the parametric variation associated with the latter effect.