Most of the research on modality in English has been devoted to the study of core modals (Bybee et al 1994; Kemenade 1993; Palmer 1979, 1986; Plank 1984; Roberts 1985; Traugott 1989; Warner 1990). As a consequence, semi-modals have been kept in a state of relative marginality. This holds particularly true in the case of ought to, as confirmed by the lack of substantial work concerning this semi-modal.
The present paper addresses the need to fill this gap by providing a description of ought to in British and American English from a short-term diachronic perspective. The study takes a top-down approach since it starts from the working hypothesis that ought to, like other modal verbs, has been gradually undergoing a process of “subjectification” (Traugott 1989, 1995). The hypothesis will be tested on the four corpora constituting the so-called ‘Brown family’ (LOB, FLOB, Brown and Frown), so as to identify any possible short-term diachronic changes in the British and American varieties under scrutiny. In order to measure how and to what extent the phenomenon of “subjectification” has affected ought to, the analysis will be carried out along semantic and syntactic lines.