Abstract
I might summarize this section by saying that the English tenses, according to this analysis, form quite a motley group. PAST, PRES and FUT serve to relate reference time to speech time, while WOULD and USED-TO behave like Priorian operators, shifting the point of evaluation away from the reference time. HAVE also shifts the point of evaluation away from the reference time, but in a more complicated way. And FUT, in contrast to PRES and PAST, is a substitution operator, putting the reference time of its clause in the plate of the speech time of subordinate clauses