Modal verbs

Modal verbs express a variety of moods or attitudes of the speaker towards the meaning expressed by the main verb in a clause

Usage

All the auxiliary verbs except be, do and have are called modals. Unlike other auxiliary verbs modals only exist in their helping form; they cannot act alone as the main verb in a sentence.

Auxiliary verbs

Be, do, and have differ from the other auxiliaries in that they can also serve as ordinary verbs in a given sentence.

Be, have and do

Can/could May/might Will/would Must Shall/should Ought to

Modal verbs

Need Dare Used to

Marginal modals

Although modal auxiliaries are classified as verbs, they alone never function as complete verbs, except in response to a question:

Can you come later? Yes, I can.

Modal verbs are always used with other verbs whose meaning they modify in some way

One modal cannot be followed immediately by another in English

Modals and other verbs

Modals are not inflected, i.e. they do not have –s or –ed forms

There are no participles or infinitives for the modals

Therefore they are often called defective verbs or anomalous verbs, i.e. not regular but deviating from the rule

Inflection

Indicates freedom to act which may be the result of ability, permission or the opportunities that circumstances provide

Ability: I can speak French. Permission: You can go now. Possibility: He could be anywhere. General characteristic: He can be difficult

at times.

Can/could

Permission: You may enter now. Possibility or probability: That gun may be

loaded. Uncertainty: How old may she be? Wishes and hopes: May you both be happy!

May/might

Obligation: You must complete this by noon. Necessity: It must be done. Deduction (logical necessity): This must be

a mistake. Advisability: You must see that movie. Certainty: If you gamble, you must lose

eventually. Must not – prohibition

Must/have to

Obligation or duty: I ought to/ should do this.

Logical necessity: He ought to be here by now.

Advisability: Tea should be drunk while it is hot.

Putative should: It is unthinkable that he should resign.

How should I know that?

Ought to/should

Decision or determination (on the part of the speaker): You shall have it.

Intention: We shall let you know our decision.

Legal shall: Everyone shall be equal before the law.

Shall

Determination: I will have my own way. Persistant habit: I will leave that door open. Characteristic habit: He will go all day

without eating. Promise: You will get your money back. An order: You will wait here till I return. Willingness: He will help you with that. Predictability: That will be the postman.

Will

Determination in the past: I would not be bullied.

Persistant habit in the past Characteristic habit in the past Promise in the past

Would

Degrees of probability Might May Could Can Should Ought to Would Will Must

Uncertain

Certain

1. Why is that man looking around like that? He _____________ be lost.

2. That woman _____________ be a doctor! She looks far too young. 3. John always fails the tests, even though he’s clever. He

_____________ study enough. 4. The food is really good at that restaurant. They _____________

have a great chef. 5. Who’s that at the door? It _____________ be Susie – she’ll still be

at work now. 6. This _____________ be John’s house. This house has a red door,

and it’s number 24, just like he said.

Can’t or must?

1. Why is that man looking around like that? He must be lost.

2. That woman can’t be a doctor! She looks far too young.

3. John always fails the tests, even though he’s clever. He can’t study enough.

4. The food is really good at that restaurant. They must have a great chef.

5. Who’s that at the door? It can’t be Susie – she’ll still be at work now.

6. This must be John’s house. This house has a red door, and it’s number 24, just

like he said.

Answer key

John is capable of typing very fast. I know how to answer this question now. I was never able to understand a word she said. It is possible that what you say is true. I had a habit of hitting the wrong key on the

keyboard. I advise you to read this book. It is obligatory for us to write a report. Is it advisable for us to wait? It is not compulsory for us to attend. You are prohibited from smoking here.

Replace the part of the sentences that have been spaced out with the appropriate modal and lexical verb:

John can type very fast. I can answer this question now. I could never understand a word she said. What you say may be true. I used to hit/would keep hitting the wrong key

on the keyboard. You should read this book. We have to write a report. Should we wait? We don’t have to attend. You must not smoke here.

Answer key

Thank you for your attention!