The clausal complementation of deontic-evaluative adjectives in extraposition constructions: a synchronic-diachronic approach

This article develops a functional synchronic-diachronic description of the clausal complementation of deontic-evaluative adjectives in extraposition constructions (ECs). It does so on the basis of qualitative and quantitative corpus-based analyses of the importance adjectives important, essential, crucial and the appropriateness adjectives appropriate, proper, and fitting. All six adjectives can currently take either mandative complements expressing desired action (coded by to-infinitives or that-clauses) or propositional complements describing arguable claims (typically coded by that-clauses). In reference grammars these have tended to receive incomplete coverage without elucidation of the constructional polysemies involved. We argue that a better understanding of the present system can be arrived at by investigating the diachronic developments by which it was fashioned. The ECs with these adjectives started off as mandative constructions and this continues to be their current unmarked use. They also developed patterns with propositional complements, but in this area the importance and appropriateness adjectives followed different diachronic paths, leading to distinct pragmatico-semantic readings of the pattern with single proposition in Present-day English.