This paper delves into some basic aspects of passive, ergative, and middle constructions in terms of transitivity, thematic relation, and syntactic derivation. Accordingly, I propose that, first of all, passives are transitive as the passive verb takes two arguments, an Agent external argument and a Theme internal argument. They are seen to be derived via NP-movement, in which the Theme internal object moves to subject position to get Case. Second, ergatives are also considered to be transitive in that they take the two arguments corresponding to those of passives. The external argument in ergatives, however, is argued to carry a non-human Causer, which is normally saturated and does not appear on the surface. The internal argument allegedly carrying a Theme theta-role is assumed to move to subject position to satisfy EPP. Finally, middles are argued to be intransitive, taking only a single internal argument with an Experiencer theta-role. The Experiencer internal argument moves into subject position to satisfy EPP and to place itself in a higher position than a Theme argument, subsequently conforming to Thematic Hierarchy, assumed in Larson (1988).
