Modal Verbs

A modal verb talks about possibility, ability, permission, obligation, or condition. The main modal verbs are:

  • can
  • could
  • may
  • might
  • must
  • ought to
  • shall
  • should
  • will
  • would

The form of a modal verb never changes, and they can only be used with a main verb. The main verb is always in the base form.


  • I should run to the shop.
    (subject/I + modal/should + main verb in base form/run)


  • I should not run to the shop.
    (subject + modal + not + main verb in base form)


  • Should I run to the shop?
    (modal + subject + verb in base form)

Negative question

  • Should I not run to the shop?
    (modal + subject + not + verb in base form)


  • John can speak German.
  • You mustn’t swim in that river.
  • Could you pass me the salt please?
  • Why couldn’t you open the box?