Modals

Modal is type of auxiliary or helping verb that is used to express ability, possibility, permission or obligation in a sentence. These modal verbs express the mode or manner of the actions indicated by the main verb.  The commonly used modals are shall, should, will, would, can, could, may, might, must, ought to, used to, need and dare. Examples of modal verbs are:

Must

Expressing: strong obligation, logical conclusion or certainty

Example:

  1. You must stop when the traffic lights turn red.
  2. He must be very tired. He’s been working all day long.

Must not

Expressing: prohibition

Example: You must not smoke in the hospital.

Can

Expressing: ability, permission, possibility

Example:

  1. I can swim.
  2. Can I use your phone?
  3. Smoking can cause cancer.

Could

Expressing: ability in the past, polite permission, possibility

Example:

  1. When I was younger I could run fast.
  2. Excuse me, could I just say something?
  3. It could rain tomorrow!

May

Expressing: permission, possibility, probability

Example:

  1. May I use your phone please?
  2. It may rain tomorrow!

Might

Expressing: polite permission, possibility or probability

Example:

  1. Might I suggest an idea?
  2. I might go on holiday to Australia next year.

Need not

Expressing: lack of necessity or absence of obligation

Example: I need not buy tomatoes. There are plenty of them in the fridge.

Should/ ought to

Expressing: 50% obligation, advice, logical conclusion

Example:

  1. I should or ought to see a doctor.
  2. He should or ought to be very tired. He’s been working all day.
  3. You should or ought to revise your lessons.

Had better

Expressing: advice

Example:  You’d better revise your lesson.