Modal verbs
作者：agustina cremona
1. Prohibition
1.1. musn't
1.2. to be prohibitted
2. Posibility
2.1. migth
2.2. may
2.3. could
3. Ability
3.1. can
3.2. be able to
4. Permisson
4.1. can
4.2. be allowed to
4.3. may
5. Obligation
5.1. must
5.2. have to
5.3. be obliged to
6. Necessity
6.1. needn't
6.2. need
7. Advice
7.1. should
7.2. ought to
8. Absense of obligation
8.1. Needn't
8.2. Don't have to
