The ultimate goal of this paper is to find a representation of modality compatible with some basic conditions on the syntax-semantic interface. Such conditions are anchored, for instance, in Chomsky's (1995) principle of full interpretation (FI). Abstract interpretation of modality is, however - be it "only" in semantic terms - already a hard nut to crack, way too vast to be dealt with in any comprehensive way here. What is pursued instead is a case-study-centered analysis. The case in point are the English modals (EM) viewed in their development through time - a locus classicus for a number of linguistic theories and frameworks. The idea will be to start out from two lines of research - continuous grammaticalization vs. cataclysmic change - and to explain some of their incongruities. The first non-trivial point here consists in deriving more fundamental questions from this research. The second, possibly even less trivial one consists in answering them. Specifically, I will argue that regardless of the actual numerical rate of change, there is an underlying and more structured way to account for the notions of change and continuity within the modal system, respectively
