Introduction

Formal criteria are primary to the establishment of word classes, but such classes typically have a notional core. Moreover, the diachronic relationship between formal and semantic characteristics needs investigation, particularly in the light of Brinton's recent claim that in a closely related area semantic change precedes syntactic change and that it is abrupt (1988: 161f.). So in this chapter I turn to two topics central to the history of modals: the development of recognizably ‘modal’ uses within a small group of verbs, the ancestors of today's group of modals, and the growing semantic coherency and isolation of that group.

The existence and status of distinctively modal uses in Old English especially needs clarification. BT gives headings which correspond to some of the distinctive areas of present-day modality in Old English, but on the whole cites less than fully convincing examples in support (see Goossens 1982 for discussion: I am rather more sceptical than he is about some of these instances). The most important semantic account for Old English is Standop (1957). He identifies the central members of the group as modalen Hilfsverben, and isolates the parameters which structure their semantic space. But he is concerned to classify the majority of uses within a historically oriented framework of sense development. Thus the synchronic significance of potentially modal uses is never focussed on as a distinct topic. On the other hand, Traugott's (1972) discussion of the sense changes undergone by these verbs from Old English is focussed on the development of grammaticalized realizations of performatives.