Aspectual constraints in the mental lexicon.

This study addresses the question of whether constraints on aspectual semantics play a role in lexical processing. Two universal cognitive constraints are identified: "states cannot be delimited" and "telic predicates cannot be further telicized." The study investigates how these are obeyed in the productive process of perfective preverb and stem combination in Bulgarian. An off-line task ascertains that Bulgarian native speakers have a default semantic interpretation for the preverbs under investigation. A visual lexical decision task shows clear legality effects in nonwords composed of existing preverbs and stems, thereby supporting decompositional approaches. It is argued that, after the process of morpheme search, there must be a process of checking for combinatory felicity of the morphemes activated in the lexical access.