express modality, especially in the Germanic languages.

Ability, desirability, permission, obligation, and probability can all be exemplified by the usage of auxiliary modal verbs in English:

:Ability: I can ride a bicycle (in the present); I could ride a bicycle (in the past)

:Desirability: I should go; I ought to go

:Permission: I may go

:Obligation: I must go

:Likelihood: He might be there; He may