An Introduction to Optimality Theory in Syntax

0. Introduction In developing generative theories of syntax the challenge has long been to reconcile two opposite kinds of empirical evidence. On the one hand, there is substantial evidence that languages of the world are deeply similar; on the other, there is also substantial evidence that they differ on the surface. For example, there are languages which allow sentences without a pronounced subject and those which do not, languages with prepositions and with postverbal objects and languages with postpositions and preverbal objects, languages which move question words to the front of the sentence and languages which leave question words inside the sentence. Historically, Principles-and-Parameters Theory (P&P), dating back to Chomsky (1981), has taken one of the possible (but potentially weak) positions on the issue and claimed that principles of UG are both universal (by definition of UG) and inviolable. A system of inviolable principles can be made compatible with the irrefutable evidence of cross-linguistic variation by appealing to parameters. For example, in earlier versions of P&P, whether a given principle is active or not at individual levels of syntactic representation in individual languages is determined by parameters. On this view, parameters circumvent inviolability by turning universal principles off. An important property of such a system is that once a principle is turned off in a language, it is predicted not to show any effects in that language. That is, parameter values are set once and for all for a given language. To take only one example, in the Minimalist Program ( Chomsky, 1995), the strength of functional features is specified in the lexicon as either strong or weak on a language-particular basis. This imposes restrictions on the computational system that work largely independently of one another. Empirically, however, the presence of a particular syntactic pattern within a given language is frequently only partial. The expletive es subject in German impersonal passives illustrates this point. Sentences (1a) and (1b), but not (1c) are grammatical: