Common modals
- can – ability: I can swim.
- must – necessity: You must stop at red.
- should – advice: You should rest.
- may – permission/possibility: You may go.
Form
- A modal is followed by the base verb: She can sing (not sings).
Key idea
Modal verbs (can, must, should, may) add meaning like ability, necessity or advice and are followed by the base verb.
Remember
Never add -s or -ed to a modal, and follow it with the base verb.