Modals

Modals

Must = have to
Mustn’t and don’t have to are different
Obligation: need to, have to, must
Lack of obligation: don’t have to, needn’t
Prohibition: mustn’t
Advice: should(n’t) ought to (not), are not supposed to, (relating to a rule)
Must and should: indicate a greater sense of speaker involvement.
Have to and ought to (not so much involvement)
Needn’t to: speaker is giving authority
You don’t need to: speaker is merely stating a fact.