English Modal Auxiliary Verbs
The verbs “can, could, may, might, will, would, shall, should, must and ought” are called ‘modal auxiliaries verbs’. They are used before the infinitives of other verbs, and add certain kinds of meaning connected with certainty or with obligation and freedom to act.
‘Have to’, ‘need’ and ‘dare’ can sometimes be used like modal auxiliary verbs, and the expression ‘had better’ is also used like a modal auxiliary.
(a) Modal verbs have no -s in the third person singular.
e.g. She can come ----------- tonight, (Not she
(b) All questions, negatives, tags and short answers are made without do.
e.g. Can you read? (Not
Do you can read?)
(c) Except ought, we use the infinitive without to after all modal auxiliaries.
e.g. She should work hard. (Not
she should to work ...)
Progressive, perfect and passive infinitives are also possible.
e.g. She may not be coming tonight.
(i) If he ran fast, he could have caught the bus.
(ii) The task ought to be done by
(d) Modal verbs do not have infinitives or participles (to can, to may, etc.) or (to may, maying, mayed, etc.). They have normally no past forms though ‘would, could, should, and might’ can sometimes be used as past tenses of will, can, shall and may.
Modal verbs are used to express the following ideas:
Can / Could / Can’t
(a) Ability: Can is used to show that someone is quite capable of doing something. We can use ‘is able to’ instead of ‘can’. Could is used in the past tense to show ability. It can be replaced with ‘was’/were able to’
e.g. (a) She can drive a car.
(b) Can you ride a camel?
(c) He can’t betray me.
(d) Could you hear what she was saying?
(b) Certainty: If we are certain that something is not true, we use can’t.
e.g. He can’t be sleeping. He has just gone out.
‘Can I’ is used to offer help to someone,
e.g. Can I get you a perfume from this shop?
(d) Permission: Can and could are used to give or ask permission to do something. Could is more-polite than can. e.g.
(a) You can leave now.
(b) Could I have your bike?
(e) Possibility: Can and could are used when we discuss the possibility of something, but we are not sure about it. - • ,
(a) He can play the first match.
(b) He could be in the squad this time.
Could is also used if there are conditions which control whether something can happen. e.g.,
I could play tomorrow, if I had the permission.
(f) Requests: Can is used when we ask someone to do something; as
(a) Can I use your mobile phone?
(b) Can you drop me over there?
May / Might
“May I” is often used in formal English for offers.
e.g. May I help you, sir?
May is used to give or ask permission to do something. It is used in formal English.
e.g. May I take your bike?
May is used when there is a discussion about the possibility but there is not certainty about it. e.g.
She might be in the classroom.
Will / Shall
(a) ‘Will’ is used when we say that something will definitely happen. It is also used to talk about something that is always true.
(a) She will come of age next year.
(b) Water will boil on heating.
(b) Intention: ‘Will’ is used when we say that we intend to do something. ‘Shall’ is sometimes used in British English with ‘I’ and ‘we’.
(a) They have informed us that they will reach before .
(b) She won’t come tomorrow.
(c) I shall appear in the trial.
(c) Offers: ‘Will’ or ‘shall’ is sometimes used to offer some help to others; as
(a) Shall I buy tickets for you?
(b) I will open the knot for you.
(d) Prediction: ‘Will’ is used when we say that something is certain to happen. ‘Shall’ is sometimes used with ‘I’ and ‘we’.
(a) I am sure, she will help me.
(b) We shall be on time, don’t worry.
(e) Requests: ‘Will’ is used for polite requests. Will you give me your bike for an hour?
‘Shall’ is used in questions to suggest something.
Shall we play now?
(a) Intention: ‘Would’ is used if there are conditions which Control whether something can happen.
e.g. I would play tomorrow. If I had permission.
(b) Requests: ‘Would’ is used for formal or polite requests. Would you give me a glass of water, please?
(a) Probability: ‘should’ is used to show that something will probably happen, though it is not completely sure.
(a) I should get a chance this time.
(b) If you take exercise daily, you should be healthy.
(b) Suggestions: ‘Should’ is used to suggest something.
You should bum oil if you want to be on top.
(a) Probability: ‘Ought’ followed by ‘to’ is used to show probability, though it is not completely sure.
I ought to reach there by evening.
(b) Suggestions/Advice: ‘Ought to’ is used to suggest something. You ought to see him if you want to get it done.
(a) Certainty: ‘Must, is used when we are sure that something is true.
(a) You must be hungry after working so hard.
(b) She must have reached by now.
(b) Necessity/Obligation: ‘Must’ is used to say that something is necessary to happen or it is necessary for somebody to do something.
(a) You must stitch your dress for the Eid.
(b) Everybody must take care of his own luggage.
(c) Suggestions/Advices: ‘Must’ is used to suggest that somebody should do something because it is good. You ‘must’ see your doctor. It’s good for your health.
(a) External Obligation:
‘Have to’ expresses external obligation:
I have to clean my feet every time I enter the room.
(b) External Authority:
‘Have to’ expresses external authority;
(a) You have to wear uniform to avoid punishment.
(b) You will have to resign the job for better future.
(c) Obligations in the Past: These are shown through the form ‘had to’.
You had to help her in her misery.
Need as an auxiliary is seldom used in the affirmative except when a negative or interrogative sentence is preceded by an expression which changes the negative or interrogative verb into an affirmative.
e.g. (a) I needn’t play the match. OR
I don’t suppose I need play the match.
(b) Need I eat dinner? OR
Do you think I need eat dinner?
Needn’t expresses speaker’s authority:
e.g. You needn’t go to bazar.
The auxiliary ‘Dare’ is generally used in negative and interrogative sentences. It is different from the ordinary verb 'dare'. It does not take - s in the third person singular present tense.
(a) She dare not call me a thief.
(b) How dare you go there?
(c) She dared not contact me.
It is used to show a discontinued habit as an auxiliary.
(a) He used to go for a walk in the morning.
(b) I used to be a good swimmer in my youth.
‘Had better’ is used to describe the best thing in a particular situation. e.g.
(a) You had better leave the room at once.
(b) She is writing for me. I had better not be late.