Optionality, Output Effects, and the EPP

This paper claims that optionality is part of the optimal design for natural language in the sense that it is bound to induce some effect on outcome which should also be some necessary part of natural language. Specifically, it is argued that the optionality in the Korean Case system, an imperfection in the minimalist sense, is justified as an apparent imperfection in terms of output effects, or Int effects (Chomsky 2000), which are shown to be two types: A-type and B-type. The A-type Int effects are weak like specificity, definiteness, thematicity, etc., being interpreted at the canonical Specs, whereas the B-type Int effects are strong like focus, specialized semantic function, etc., being interpreted at the non-canonical Specs. The A-type Int effects are claimed to be due to lexically-posited EPP-features whereas the B-type Int effects are claimed to be due to derivationally-introduced EPPfeatures. Lexically-posited EPP-features are either obligatory or optional whereas derivationally-introduced EPP-features are only optional. It is shown that the interface strategy in terms of output Int effects is superior to Hiraiwa s (2002) φ-over-φ generalization in the accounts for obligatoriness of the EPP-feature.