ABSTRACT
This final section will turn to investigate a further ‘gap’ of standard English. As Table 2.13 in Chapter 2 has shown, in standard English there is a gap in the system of negated modals: the form mustn’t, where the main verb is negated, only has deontic meaning (e.g. You mustn’t do that meaning ‘You are obliged not to do that’). The epistemic meaning of positive must (necessity) cannot be negated by using must; this meaning (‘It is necessary that . . . not’) is usually substituted by cannot, e.g. His absence must have been noticed can only be negated in the following way: His absence can’t have been noticed.17
