This thesis focusses on the interaction of regularity and irregularity in combinatorial semantics, i.e., in the interpretation of complex syntactic structures. The empirical domain of the study lies within the varying degree of syntactic and semantic regularity apparent in the continuum between free combinations ("read a book"), (more or less flexible) idiomatic expressions ("spill the beans"), and fully fixed expressions ("trip the light fantastic").
The thesis extends the architecture of grammar of Head-Driven Phrase Structure Grammar (Pollard and Sag 1994) with a model-theoretic semantics and with an irregularity module. The former is located in the CONTENT value of a linguistic sign, the latter in the value of a new feature, COLL (Context Of Lexical Licensing).
It will be argued that the new architecture for semantics has considerable advantages over the architecture of Pollard and Sag 1994, and that the treatment of idiomatic expressions meets the requirement for an integrated treatment of regularity and irregularity in natural language.