Modals Verbs: Can - Cannot - Can't

Can is a modal verb.

Can is used to express ability or to say that something is possible.

Can is the same for all subjects. We don't add an 'S' in the third person (like other verbs)

The verb that comes after Can is in the infinitive without to:

• I can speak Spanish. (= it is possible for me to speak Spanish = I have the ability to speak Spanish)
• He can swim well.
• We can see our neighbour in the garden.
• They can play the guitar.

Negative

To form the negative we add "not" after can to form one word: cannot.

We can also contract the negative to form can't. (can't = cannot)

• I cannot play the piano. We can't go to the cinema tonight.
• She cannot speak French very well. He can't drive a car.

Questions

To from the question we change the position of the subject and the auxiliary verb.

The main verb is still in the infinitive without to.

• Where can I buy an ice-cream?
• Can I go to the party, please?
• Can you speak Japanese?
• What can we do on Saturday?

Remember that you can use short answers:

• Can I sit here please? Yes, you can.
• Can you speak Chinese? No, I can't.

Impersonal Can

Sometimes You can and Can you…? are impersonal and refer to people in general.

• You can see many stars at night from here. (= people in general can see many stars)

It doesn't necessarily refer to you but people in general.

• You can't run naked in the middle of the street.

Not necessarily saying YOU can't run naked in the middle of the street but in general it is not possible for anyone.

Modal Verbs - Should, Shouldn’t, Ought To Explanations and Exercises

Shall, Should, Ought to

To Offer of Assistance or Polite Suggestion (When you are quite sure of a positive answer)

Shall + subject + base form of the verb

1.    Shall we go for a walk?

Note: Shall is only used with I or we. It is used instead of will only in formal English.

To Offer of Assistance or Polite Suggestion (When you are not sure of a positive answer)

Should + subject + base form of the verb

1.    Should I call a doctor?

A Prediction or Expectation that Something Will Happen

should/shouldn’t + base form of the verb

1.    The proposal should be finished on time.

2.    I shouldn’t be late. The train usually arrives on time.

To Give Advice

should / ought to + base form of the verb

1.    You should check that document before you send it out.

2.    You ought to have your mobile phone serviced before the holiday.

To Give Advice (about something you think wrong or unacceptable)

shouldn’t + base form of the verb

1.    James shouldn’t teach him words like those.

Exercises: Should, Shouldn’t, Ought To

Fill in should, shouldn’t or ought in the following sentences as in the example.

1.    He shouldn’t encourage such bad behavior.

1.    You _____ get your teeth cleaned at least once a year.

2.    The house ______ be ready to move into by next month. It’s almost finished.

3.    Ron ________ to improve his attitude. If he doesn’t, he might get fired.

4.    ________ I get your jacket? It’s cold in here.

5.    You ________ put your feet on the table. It’s not polite.

Answers:

1.    should

2.    should

3.    ought

4.    shall

5.    shouldn’t

Modal Verbs - May, Might Explanations and Exercises

May, Might

Formal Permission / Formal Prohibition

may / may not + base form of the verb

1.    You may start your exam now.

2.    You may not wear sandals to work.

Polite Request

May + subject + base form of the verb

1.    May I help you?

Possibility / Negative Possibility

may/ might + base form of the verb

1.    We may go out dinner tonight. Do you want to join us?

2.    Our company might get the order if the client agrees to the price.

may not / might not + base form of the verb

1.    Adam and Sue may not buy that house. It’s very expensive.

2.    They might not buy a house at all.

To Make a Suggestion (when there is no better alternative)

may as well / might as well + base form of the verb

1.    You may as well come inside. John will be home soon.

2.    We might as well take Friday off. There’s no work to be done anyway.

Polite Suggestion

might + base form of the verb

1.    You might like to try the salmon fillet. It’s our special today.

Exercises: May / Might

Fill in the correct form of may or might as in the example.

1.    May I sit here?

1.    They ______ finish the project on time. The main engineer is ill.

2.    You _____ want to stop by the museum gift shop on your way out.

3.    _____ I have your autograph?

4.    He _______ visit the Louvre. He’s in Paris anyway.

5.    You ______ park your car here. It’s reserved for guests of the hotel only.

Answers:

1.    might not

2.    might

3.    May

4.    may as well

5.    may not

Modal Verbs - Can, Could, Be Able To Explanation and Examples

Can, Could, Be Able To

Can, could and be able to are used to express a variety of ideas in English:

Ability/Lack of Ability

Present and Future:

can/can’t + base form of the verb

1.    Tom can write poetry very well.

2.    I can help you with that next week.

3.    Lisa can’t speak French.

am / is / are / will be + able to + base form of the verb
am not/ isn’t / aren’t/ won’t be + able to + base form of the verb

1.    Mike is able to solve complicated math equations with his mobile phone.

2.    The support team will be able to help you in about ten minutes.

3.    I won’t be able to visit you next summer.

Past:

could / couldn’t + base form of the verb

1.    When I was a child I could climb trees.

was / were + able to + base form of the verb
wasn’t / weren’t + able to + base form of the verb
hasn’t / haven’t + been able to + base form of the verb

1.    I wasn’t able to visit her in the hospital.

2.    He hasn’t been able to get in touch with the client yet.

Note: Can and could do not take an infinitive (to verb) and do not take the future auxiliary will.

·         Incorrect: I can to help you this afternoon.

·         Correct: I can help you this afternoon.

·         Correct: I will (I’ll) be able to help you this afternoon.

Possibility / Impossibility

can / can’t + base form of the verb

1.    You can catch that train at 10:43.

2.    He can’t see you right now. He’s on the phone. 

could + base form of the verb

1.    I could fly via Amsterdam if I leave the day before.

Ask Permission / Give Permission

Can + Subject + base form of the verb (informal)

1.    Can you lend me ten dollars?

Can + base form of the verb (informal)

1.    You can borrow my mobile phone.

Could + subject + base form of the verb (polite)

1.    Could I have your number?

2.    Could I talk to your supervisor please?

Make a suggestion – To make a suggestion use:

Could + base form of the verb (informal)

1.    You could take the tour of the castle tomorrow.

Exercises: Can, Could, Be able to

Fill in the correct form of can, could or be able to as in the examples.

1.    Ben could not help his little brother with his homework yesterday.

2.    Can I call you later tonight?

1.    _______ Tony run long distances when he was a boy?

2.    ______ you please call a tow truck for me? My car broke down. (polite)

3.    The students _______ to buy their textbooks today. The bookstore is all out of them.

4.    ______ you teach me how to fix my mobile phone? You’re so good at it.

5.    ______ you ______ reach the customer if you call him at 4:00 his time?

Answers:

1.    Could

2.    Could

3.    aren’t able

4.    Can

5.    Will/be able to