Testing the Principle of No Synonymy across levels of abstraction

This corpus-based study tests the Principle of No Synonymy across levels of abstraction by examining the syntactic realizations of subject extraposition (e.g., it is important to, it seems that), and by investigating at which level(s) of formal description a difference in form also entails a difference in function. The results show that distinct pairs of form and function, i.e. constructions, can be found at different levels of abstraction, but that these constructions also subsume formal realization patterns that do not encode a difference in function. This suggests that the Principle of No Synonymy largely breaks down at low levels of formal description. The study also offers a constructional account of subject extraposition by identifying a number of subject extraposition constructions, thereby showing that this is a syntactic phenomenon that is best analyzed as a family of constructions.