What are Modal Verbs?

Modals, or modal verbs, are special verbs that act differently from normal verbs like study, work, or play. Modals provide more information about how the main verb function. They have several varieties of communicative functions.

Examples :

  • You must study hard to succeed.
  • Can you help me with my homework?
  • May I have a cup of tea, please!
  • Could you close the window?
  • You must be quiet during exams.

Characteristics of modal verbs:

  • Modals stay as they are. They never change their form that is to say you cannot add endings such as “s” “ed” or “ing”.
  • They are always followed by an infinitive without the bare infinitive “to”.
  • The use of modal verbs allows speakers to express ability, obligation, certainty possibility, etc.

List of modal verbs in English:

Can, may, will, would, shall, should, must, could.

When to use

Modal verbs can be used to express:

  • 1. Permission 
  • 2. Ability
  • 3. Obligation
  • 4. Prohibition
  • 5. Lack of necessity
  • 6. Advice
  • 1. possibility
  • 8. probability

More examples:

The following table contains all modal verbs in English along with expressing and examples for each:

Modal VerbExpressingExample
BetweenStrong obligationYou must stop when the traffic lights turn red.
logical conclusion / CertaintyHe must be very tired. He’s been working all day long.
CanabilityI can swim.
permissionCan I use your phone,please?
possibilitySmoking can cause cancer.
Couldability in the pastWhen I was younger, I could run fast.
polite permissionExcuse me, could I just say something?
possibilityIt could rain tomorrow!
MaypermissionMay I use your phone, please?
possibility, probabilityIt may rain tomorrow!
Mightpolite permissionMight I suggest an idea?
possibility, probabilityI might go on holiday to Australia next year.
Need notlack of necessity/absence of obligationI need not buy tomatoes. There are plenty of tomatoes in the fridge.
Should/ought to50 % obligationI should / ought to see a doctor. I have a terrible headache.
adviceYou should / ought to revise your lessons
logical conclusionHe should / ought to be very tired. He’s been working all day long.
Had betterAdviceYou’d better revise your lessons