Models
Advice
(PR) Had better to do
(PR) Ought to
(PR) Should
Permission
(PAST) Could (for reported)
(PAST) Be allowed to
(PR) Can (unpolite)
(PR) Could (less polite)
(PR) May (most polite)
Ability
(PAST) Could have V3 (for unreal situation)
(PAST) Could (for past situation(real))
(PR) Could (for unreal)
(PR) Can (for present and future situations)
Degrees of certainty
Posibility
(PR) May, could, might
(PAST) may, could, might + have V3
Probability
(PR) Should, ought to
(PAST) should, ought to + have V3
Certainty (90-99%)
(PR) Must, can't, couldn't
(PAST) must, can't, couldn't + have V3
Obligation
(PAST) Needed to (didn't need to)
(PAST) Need have V3 (nedn't have done(V3))
(PAST) Had to (didn't have to)
Be supposed to
(PR) Need to
Don't need to
Needn't
(PR) Have to (don't have to)
(PR) Must (must not)
Criticism
(PAST) Ought (not) to have done(V3)
(PAST) Should (not) have done(V3)
