Modal verbs

Modal verbs have special characteristics

1)They are auxiliaries. You don’t use auxiliary verbs with them. You say:

I shouldn’t eat a lot of hamburgers.

NOT I don’t should eat a lot of hamburgers

You say:

Can I go to the toilet?

NOT Do I can go to the toilet?

More special characteristics

2) They don’t change with the 3rd person singular.

I must wake up early → She must wake up early

I may go to your party → He may go to your party

I could jump very high → It can jump very high

More special characteristics

3) They are followed by the INFINITIVE (base form).

You say:

Kevin must study for his exam.

NOT

Kevin must studies for his exam.

More special characteristics

4) They don’t have gerunds or participles.

You DON’T SAY:

Kevin is musting study today

Kevin has musted study today.

Not all modals are the same

●Most modals don’t use the preposition to:

You should study

She must drive her father’s car

I would like to go to that concert

Not all modals are the same

BUT some modals need the preposition to:

You ought to study

She has to study

I used to live in Korea

Not all modals are the same

Two modal verbs are actually semi-modals. They change in the third person singular. They are HAVE TO and NEED TO.

Laura has to work on Sunday

Paul needs to clean the kitchen

Jean doesn’t have to go to the office

Not all modals are the same

They also have a past form.

Laura had to work on Sunday

Paul needed to clean the kitchen

Jean didn’t have to go to the office

Most of the other modals don’t.

obligation modals

must and have to

We use must and have to to express obligation.

You must bring a bottle of water to the gym.

You have to wear sport shoes to the gym.

must and have to

They change meaning when they are negative:

You mustn’t bring food to the gym. (It’s forbidden)

You don’t have to bring your MP3. (You can if you want to)

must and have to

It’s not very common to make questions with must.

Must I go every day? → 😶❔

We usually make questions with have to.

Do I have to bring a towel?→ 😊 ✓

need/ needn’t

You can also use need to to express necessity or obligation.

I need to take these documents to my boss.

In the negative, needn’t means lack of obligation.

You needn’t bring your MP3 to the gym.

modals for advice

should / ought toWe use should and ought to to give advice.

You should eat more fruit

You ought to visit your grandmother

You shouldn’t drive so fast

Should I buy that shirt?

It’s not very common to use ought to in the negative (oughtn’t) and interrogative forms.

modals for ability

can / could / be able to

We use can to express our ability to do something.

Beyonce can sing very well.

Louis can’t play the piano.

Can you run 12 kilometres?

can / could / be able to

Unlike many modals, can has a past form, could.

Pavarotti could sing very well.

Napoleon couldn’t conquer Russia.

Could you arrive to the theatre on time yesterday?

can / could / be able to

For the future and other times, we use be able to:

I will be able to see Kim in London this summer.

I won’t be able to go to your party.

He’s been able to finish his homework in 6 minutes.

Jane hadn’t been able to talk to her mum in Australia.

permission

We can also use can / could to ask for permission. Could is more polite. You can also use may.

Can I go to the toilet? No, you can’t.

Could I use your phone? No, I’m sorry.

May I come in? No, you may not.

suggestions and offeringsYou can make suggestions and offerings with can. Could is more polite.

You can use my computer if you want to.

You could try the subway next time.

You can also use shall. This is old-fashioned and polite.

Shall we dance?

You can also use would to make polite offerings

Would you like to dance?

modals for speculation

We are not very sure

When we are not sure of something, we can use could, may, might.

It may be Karen’s boyfriend.

It could be Karen’s boyfriend.

It might be Karen’s boyfriend.

We’re positive

We usually use must.

It must be Karen’s boyfriend. She’s kissing him.

When something is impossibleWe usually use can’t.

It can’t be Karen’s boyfriend. He lives in France.

can’t / cannot /couldn’t

You can use can’t and cannot to forbid something.

You can’t smoke in school.

BUT you musn’t use couldn’t to make it more polite. It means you weren’t able to do something in the past.

You couldn’t smoke in school in 1979.

Modals in the past :modal perfect verbs

how to use them

Because we usually can’t use the past tense with modals, you add have in the infinitive form and a participle. That is, you say things like:

I must have forgotten my wallet.

He may have missed the bus.

modal perfects for speculation: not sureI saw Karen with someone yesterday.

It may have been her boyfriend.

It might have been her boyfriend.

It could have been her boyfriend.

we’re sure

They were kissing.

It must have been her boyfriend.

it’s impossible

When it’s your opinion:

It can’t have been her boyfriend. I think he doesn’t live in Madrid.

When you have evidence to know it’s impossible.

It couldn’t be her boyfriend. Lisa saw him in Bilbao yesterday.

For extra practice:

For more information and exercises, you can also visit:

BBC Learning English (possibility)

BBC Learning English (speculation)

Learn English Teens -British Council

http://www.agendaweb.org/verbs/modals-exercises.html