The greater or lesser degree of prototypicality is given by the number of typical constructions of the class the verbs participate in: each class contains a group of "core" verbs that share all the syntactic and semantic characteristics of the general class, and fuzzy boundaries of less prototypical members.
we argue that specific semantic properties of a specific verb meaning may "block" the realization of some constructions that are instead shared by most of the other verbs of a class, or instead add some idiosyncratic constructions as well.