Modal Verbs - by Viv Quarry (www.vivquarry.com)

 

In order to understand English modal verbs, it is important to recognise how they can be used. Modal verbs in English can be used in TWO WAYS:

 

1.   To show LEVELS OF PROBABILITY (deduction).

 

2.   To perform SPECIFIC FUNCTIONS (additional meaning) like obligation, permission etc.

 

MODAL VERBS USED TO SHOW LEVELS OF PROBABILITY

 

LEVEL OF

PROBABILITY

MODAL

VERB

TIME =

PRESENT & FUTURE

TIME =

PAST

 

 

 

 

CERTAINTY

WILL (Be)

He'll be here by Friday.

That will / would have been Susan who called.

 

CERTAINTY

 

WON'T (Be)

 

She won't be here.

It won't / wouldn't have been John, I think he's in São Paulo.

 

 

 

 

IMPOSSIBILITY

CAN'T Be

COULDN'T Be

It can't be Fred, he's in the USA.

It couldn't be right.

He can't / couldn't have written this, he doesn't speak Arabic.

 

 

 

 

PROBABILITY

(LOGICAL)

MUST (Be)

 

He must be right, he's an expert in this area.

He must have finished by now, he's a fast worker.

PROBABILITY

(LOGICAL +

PREFERENCE)

SHOULD (Be)

He should be finishing now, he's a fast worker.

He should have finished by now, the exam's nearly over.

 

 

 

 

POSSIBILITY

MIGHT (Be)

They might win, but I doubt it.

If they had played better, they might have won.

POSSIBILITY

MIGHT NOT (Be)

It's very cloudy, but I might not rain.

If I hadn't read that book I might not have passed the exam.

 

 

 

 

POSSIBILITY

MAY (Be)

We may go to Greece for our holidays.

She may have got lost.

POSSIBILITY

MAY NOT (Be)

I may not arrive on time.

He may not have done it.

 

 

 

 

POSSIBILITY

COULD (Be)

You could be right, but I doubt it.

He could have had an accident even though he's a very good driver.

 


MODAL VERBS USED TO PERFORM SPECIFIC FUNCTIONS

 

FUNCTION

MODAL

VERB

TIME =

PRESENT& FUTURE

TIME =

PAST

COMPULSION

MAKE SB (Do)

She makes them tidy their room.

The teacher made them write it out six times.

PROHIBITION

CAN'T/NOT ALLOWED TO

My dad says that I can't see you anymore.

She wasn't allowed to see him anymore.

PERMISSION

MAY (Be)

May I go now?

I was allowed to go.

STRONG

OBLIGATION

MUST (Do)

I must remember to pay the phone bill.

I had to apologize.

STRONG

OBLIGATION

MUSTN'T (Do)

Mother: "you mustn't play with matches."

The children weren't allowed to play outside.

NO OBLIGATION

DON'T HAVE TO (Do)

I don't have to wake up early on Saturdays.

I was happy that I didn't have to see him again.

NO OBLIGATION

NEEDN'T (Do)

You needn't pay it now if you don't want to.

You needn't have done it, but I'm glad you did.

NO OBLIGATION

DON'T NEED TO (Do)

I don't need to study French anymore.

He didn't need to revise for the exam.

DUTY

SUPPOSED TO

Your supposed to arrive at work at 8am.

You were supposed to have done this by now.

DUTY

NOT SUPPOSED TO

You not supposed to be here!

I wasn't supposed to have been at the meeting.

FORMAL

ADVICE

WOULD (Do)

I'd arrive on time if I were you.

I would have arrived on time if I'd been him.

FORMAL

ADVICE

WOULDN'T (Do)

I wouldn't do that if I were you.

I wouldn't have done that if I'd been him.

INFORMAL

ADVICE

SHOULD (Do)

You should always dress well at interviews.

You should have dressed well at the interview.

INFORMAL

ADVICE

SHOULDN'T (Do)

You shouldn't speak to him like that.

You shouldn't have spoken to him like that.

INFORMAL

ADVICE

OUGHT TO (Do)

You ought to be here earlier.

You ought to have been there earlier.

INFORMAL

ADVICE

NOT OUGHT TO (Do)

You didn't ought to touch that.

You didn't ought to have done that.

REQUESTS

CAN (I/you)

Can/Could you help me, please?

I asked him to help me.

ABILITY

CAN (Do)

I can speak English.

I could speak English when I was five.

ABILITY

BE ABLE TO (Do)

Will you be able to come?

She was able to answer all the questions.

ABILITY

MANAGE TO (Do)

Does he manage to get here on time?

He managed to rescue her.

NORMAL

BEHAVIOUR

WILL

She'll always do her homework.

She would always do her homework.

OFFERS

WILL

I'll help you with that.

I'd have helped you.

OFFERS

SHALL

Shall I give you a hand.

I should have helped you.

SUGGESTIONS

SHALL (LET'S)

Shall we meet at 9pm?

I suggested meeting at 9.

WILLINGNESS

WON'T (Do)

I won't do it!

She wouldn't do it.


Before using a modal verb, you must decide whether you are using it to show probability or possibility.

 

If the answer to this question is YES, then the present and future form will be:

 

                                                                                    +          VERB +          OBJECT

                                                MODAL VERB         +          BE       +          NOUN / ADJECTIVE

                                                                                    +          BE       +          GERUND

 

E.g.       They may arrive on time.                                             or

 

            He might be the right person for the job.                      or

 

            She should be arriving in a few minutes.

 

and the past form will be:

 

                                                MODAL VERB         +          PRESENT PERFECT

 

E.g.       It must have been a very difficult exam, everyone's looking worried.

 

If the answer to the question above is NO then things are much more complicated and you will have to learn the modal verb used, and its past tense form, depending on the function.

 

Modal verbs - Difficult cases

 

Probability and possibility.

 

CAN

 

'Could be' or 'could have been' mean that something is possible but you are NOT CERTAIN.

 

E.g.       "Where's John?"

            "I don't know. He could still be at home" or

            "I don't know. He could have gone home" (I've got no idea, it's just a guess)

 

BUT 'Can't be' or 'can't have been' are used to say that something is not possible: you are CERTAIN.

 

E.g.       "Where's John?"

            "I don't know. He can't still be at home because I've just come from there." or

            "I don't know. He can't have gone home because his car's still here." or

            "I don't know. He couldn't have gone home, I've just seen his car."

            ('Couldn't be' has the same meaning but is slightly weaker)

 

Specific functions

 

MUST AND HAVE TO

 

'Must' is used when the speaker has AUTHORITY to oblige someone to do something.

 

E.g.       (Doctor to patient)        "You must stop smoking immediately."

            (Mother to child)          "John. You mustn't speak like that to your grandmother."

            (To yourself)                 "I must remember to buy my mother a present."


THE PAST OF 'MUST' IS 'HAD TO'.

 

E.g.       I had to remember to take my car keys with me when I went to the airport.

 

When the obligation comes from another person or organization, HAVE TO is used.

 

E.g.       "I have to get up early tomorrow." (My job or a trip is obliging me to get up early)

            "How many years do you have to work before you can retire?" (Obligation from rules)

 

Note! the pronunciation of 'have to' is /HAFTA/

 

Only 'Have to' is possible in the will future or the present perfect.

 

'MUSTN'T' means that there is an obligation NOT TO DO SOMETHING.

 

BUT 'DON'T HAVE TO' means that there is NO OBLIGATION.

 

E.g.       (Teacher to student)      "You mustn't forget to revise your modal verbs before the exam,

                                                but you probably won't have to answer any difficult questions"

 

The past of mustn't is 'not be allowed to'.

 

E.g.       "My mother told me that I wasn't allowed to talk to strange men."

 

CAN FOR ABILITY

 

'Can' (do something), 'can't' (do something) and 'couldn't' (do something) are used with stative verbs and when the ability is GENERAL.

 

E.g.       "When the light went off I couldn't see anything." (stative verb)

            "I could swim when I was six years old." (I could swim at any time after 6 years old)

 

When you want to talk about ABILITY ON ONE SPECIFIC OCCASION you must use BE ABLE TO or MANAGED TO.

 

E.g.       I wasn't able to fix the engine because I didn't have the parts I needed.

 

Managed to is used to stress the successful completion of the activity.

 

E.g.       The girl was drowning, but the lifeguard managed to save her.

 

In the present 'can' and 'be able to' are sometimes interchangeable, but in the will future or in perfect tenses, 'be able to' or 'managed to' must be used.

 

REQUESTS

 

The modal verb which is used for a request depends on THE LEVEL OF FORMALITY.

 

In FORMAL SITUATIONS you can use WOULD or DO YOU MIND (DOING STH.).

 

E.g.       "Would/Do you mind if I open the window?" or

            "Would you mind turning down the music a bit?" (Talking to someone you don't know well)


In INFORMAL SITUATIONS use CAN (YOU DO STH.).

 

E.g.       "Dad, can we go to the cinema on Saturday?" or

            "John, can you pass me that book?" (Talking to a good friend or a member of your family)

 

In nearly ALL SITUATIONS you can use COULD (YOU DO STH. FOR ME).

 

E.g.       "Could you help me with this exercise, please?" or

            "Could I have six pounds of potatoes, please? (At home, in class or in shops)

 

OFFERS

 

WILL and SHALL are used when making offers.

 

WILL means I'M OFFERING TO HELP YOU.

 

It is usually used when you are talking to someone you know well, and it is obvious that you can help them.

 

E.g.       "Oh dear. There are so many dishes to wash!"

            "I'll help you do the washing up."

 

SHALL means I'M ASKING YOU IF YOU WANT ME TO HELP YOU.

 

It is usually used when you are talking to someone you don't know very well or when it is not clear that you can be of help.

 

E.g.       "Oh dear! These suitcases are very heavy."

            "Excuse me. Shall I help you with them?"  (Two people who don't know each other) or

            "I'd like to go to a party next Friday, but I haven't got anyone to look after my son."

            "Shall I baby-sit for you?" (I'm not qualified, but I'll help you if you like)

 

SHALL can also be used to make a suggestion. E.g. "Shall we go to the cinema tonight?"

 

WILL FOR CHARACTERISTIC BEHAVIOUR

 

When using this structure it should be contracted when writing and not stressed when speaking.

 

E.g.       "He'll always be there when you need help."

 

If it is stressed when speaking, it means that the behaviour is annoying.

 

E.g.       "He will keep on interrupting me."

 

NEEDN'T HAVE DONE v DIDN'T NEED TO DO

 

Needn't have done sth. means the action was completed, but was unnecessary.

E.g.       "You needn't have bought any butter. We've got lots of it."

 

Using 'didn't need to do sth.', we don't know if the action was completed, just that it wasn't necessary.

E.g.       "I didn't need to do any shopping because I was eating out that night."

 

Modal verbs practice exercises (advanced level)

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