Thematic Roles and Syntactic Structure*

One central task for any theory of grammar is to solve the so-called “linking problem”: the problem of discovering regularities in how the participants of an event are expressed in surface grammatical forms and explaining those regularities. Suppose that one adopts a broadly Chomskyan perspective, in which there is a distinction between the language faculty and other cognitive faculties, including what Chomsky has recently called the “Conceptual-Intensional system”. Then there must in principle be at least three stages in this association that need to be understood. First, there is the nonlinguistic stage of conceptualizing a particular event.1 For example, while all of the participants in an event may be affected by the event in some way or another, human cognizers typically focus on one or the other of those changes as being particularly salient or relevant to their interests. This participant is taken to be the “theme” or “patient” of the event, perhaps in some kind of nonlinguistic conceptual representation, such as the one developed by Jackendoff (1983, 1990b). Second, this conceptual/thematic representation is associated with a linguistic representation in which the entity seen as the patient of the event is represented as (say) an NP that is the direct object of the verb that expresses what kind of an event it was. This is the interface between language and the conceptual system. Finally, there is the possibility of adjusting this representation internally to the language system, by way of movements, chain formations, Case assignment processes, or whatever other purely syntactic processes there may be. For example, the NP that represents the theme and starts out as the direct object of the verb may become the subject if there is no other subject in the linguistic representation, either because there was no agent in the conceptual representation (as with an unaccusative verb), or because it was suppressed (as with a passive verb). Since there are at least these three stages between an event and a surface-linguistic description of it, there is room for a good deal of complexity in theory and analysis. Therefore, most syntactic theorists assume that at least one step in the association is relatively trivial. In part, this is a tactical move, an effort to cut down the number of analytic choices that a theory must make in order to develop an analysis of any particular phenomena. However, the need for restrictions also seems to be empirically motivated by the fact that there are in fact important linking regularities both within and across languages. How extensive these regularities are is a matter of debate, but to the extent that they exist, there must be a fair amount of rigidity in the system. Outside of Chomsky’s Principles and Parameters (P&P) framework, the most popular way to constrain the linking problem is at the third stage: to say that there is essentially no difference between the initial grammatical representation and the surface grammatical