Modal Verbs

What are Modal Verbs?

Modal (auxiliary) verbs are special class of verbs that differ from ordinary English verbs in form and function. They are used to talk about things which we expect, which are or are not possible, which we think are necessary,  which we want to happen, which we are not sure about, which tend to happen or which have not happened.

Modals have a single invariant form, i.e. they never end in -s, even in sentences with third-person singular subjects (noun or pronoun), and they do not add -ed to signal past tense.

What are the Types of Modal Verbs?

The meanings expressed by modals can be generally grouped into three:

1. Permission, Possibility, and Ability: can/could, may/might

  • Can I borrow your pen for a minute?/May I borrow your pen for a minute?
  • Even expert writers can make mistakes.
  • It is healthy to be reminded that the strongest might weaken and the wisest might err.
  • If you don't know where you are going, you might wind up someplace else.
  • We may never return to Paris.
  • My only fear is that I may live too long.
  • Can you memorize all the numbers on the board?

2. Obligations and Necessity: must, have to, need, should, ought to

  • You must love your neighbor as yourself.
  • You need not worry about the exam.
  • We have to be back by 11 o'clock or my mom will freak out.
  • Donald should really brush his teeth. 
  • You ought to listen to your doctor.

3. Volition (intention, willingness, and insistence) and Prediction: will/ would, shall

  • I'll (will) email you as soon as I can. 
  • I'll (will) help you, if you like.
  • We would like to live as we once lived, but history will not permit it.
  • Life would be infinitely happier if we could be born at the age of eighty and gradually approach eighteen.
  • Norton shall/will win quite easily.  


  •  A Comprehensive Grammar of the English Language by Randolph Quirk, Sidney Greenbaum, Geoffrey Leech, and Jan Svartvik (Longman Group Ltd., 1985)
  • The Teacher's Grammar Book (2nd Edition) by James D. Williams (Lawrence Erlbaum Associates, Publishers, London, 2005)
  • Practical English Usage by Michael Swan (Oxford University Press, 2009)
Designed by Neil Yamit