Modal Verbs are auxiliary verbs (helping verbs) and are always used alongside another main verb. Modal verbs and are used to indicate the modality of an event, that is, the likelihood of something happening.
They express if something is certain, probable, possible, improbable or impossible.
Modal verbs are also often used to increase the politeness of a request. Modal verbs are used in this way in English all the time to create a sense of politeness and good manners.
Modal verbs are also used to talk about permission, requests obligations and offers.
The modal verbs are:
Would / will
Could / can / be able to
Might / may
Should / shall
Modal verbs to talk about probability
Modal verbs express if something is certain, probable or possible.
If something is possible in the future, we use ‘could’, ‘might’ or ‘may’ before the main verb to talk about it.
It could rain tomorrow (but it might not)
The glass might break if you drop it (but it might not)
She may go on holiday (but she might not)
Modal verbs and ‘have’
If something is possible now or was possible in the past we add the word ‘have’ after the modal verb. This still expresses possibility.
It could have rained today
We could have won the game
The glass might have broken (if you had dropped it)
She might have gone on holiday
He might have left already
General situations in the present and past
We can use the word ‘can’ to talk about current general situations with modal verbs. We can also use the word ‘could’ to talk about past general situations.
It can get very hot in the summer (meaning: it is often hot in the summer)
It could get very cold by the sea (meaning: it used to often get cold by the sea)
We add the word ‘not’ after the modal verb to make it negative. In contracted speech we change this to ‘can’t’. We also use ‘never’ to make it clear that under no circumstances could something happen.
For talking about an event in the past, we use ‘could not’ or ‘couldn’t’
He can’t walk into town in those uncomfortable shoes
They can’t hope to repair the car in time for the race
We couldn’t have won the game
We could never have won the game (more emphasis)
If something is probably true, we use the word ‘must’ before the main verb to talk about it.
It must be time for dinner – it’s almost 8pm.
We have £50. That must be enough to buy the tickets.
It’s raining. You must be soaked!
Probable events in the past
To talk about a probable event in the past we use ‘must have’:
You must have been scared on that rollercoaster
It must have been pleasant living by the sea
They must have caught the train they were so fast
It was late. They must have been hungry.
They were late for school. The must have slept in.
Probable events in the future
To talk about a probable event in the future we use ‘should’.
The timetable says the train arrives at 6pm, so it should be here soon.
We should have enough food. There are only 3 people coming for dinner.
You studied hard so you should pass the test.
Modal verbs to talk about ability
We use the word ‘can’ to talk about abilities in the present tense. The word ‘not’ makes it negative.
We can also use the phrase ‘to be able to’ in the same way as ‘can’ and ‘can’t / cannot’ to talk about ability.
He can talk French
She can play the piano
I am able to salsa dance
He is not able to paint
They can ski really well
We use the word ‘could’ to talk about abilities in the past tense. We still use a present tense verb after ‘could’. The word ‘not’ makes it negative.
He could talk German
She could play the flute
They couldn’t play football
We couldn’t go on holiday last year because we didn’t have enough money
Possible events that did not happen
We use the phrase ‘could have’ to talk about a possible event that did not happen. We use a past tense verb after ‘could have’.
She could have played the violin well if she had practised
He could have gone to Spain if he had wanted to
They could have bought a house if they had saved enough money
Modal verbs for benefit or advantage
Might as well / May as well
May and might are used in English to express the idea that if Y has the same advantages or disadvantages as X (they are equally attractive options), you ‘might as well’ do Y.
If the car is just as slow as the train, I may as well take the train
This idea often has a feeling of frustration, irritation or resignation about it. The idea can sometimes be difficult to explain to non-native English speakers and equally difficult to understand. So hopefully these further examples will help:
It is raining now, so I might as well stay at home
I was going to stay up to see you, but as you won’t be back until tomorrow, I may as well go to bed
He didn’t understand my meaning. I may as well have been speaking in a foreign language
I am trying to see the stars, but it is so cloudy, I may as well be looking at a brick wall
You will have to give me instructions and it will take so long, you might as well do it yourself
The tea tasted so horrible, it might as well have been mud
Modal verbs to talk about permission
We use the word ‘can’ to ask permission for something. We use the word ‘could’ in the same way to be more polite. We can also use the word ‘may’ to be extra polite – this sounds quite formal.
Can we buy food here?
Can I smoke here?
Could they borrow that book?
Could you write your name on the form, please?
May I use this pen?
May we leave now?
We use the words ‘can’, ‘could’ and ‘may’ to give permission. ‘Can’ is the most common and ‘may’ is more formal.
You can borrow my book if you like.
They could join the gym if they want.
You may leave now if you wish.
Modal verbs to make requests
We use the words ‘could’ and ‘would’ to make requests.
Could you pass the salt, please?
Could I have the bill now, please?
Would you lend me your book?
Would you mind if I left early?
Modal verbs for advice and suggestions
We use the word ‘should’ to give advice to someone. The word ‘should’ is quite strong. The implication is that there is only one good option. The word ‘ought’ is also used for suggestions (‘ought’ is pronounced ‘ort’).
You should park your car there – it is nearer to the shops
We should aim to arrive early. It is more polite.
They should never have gone to the party. It was boring.
It is cold. You should wear a coat.
It is cold. You ought to wear a coat.
We use the word ‘could’ to make suggestions. The word ‘could’ is less strong than ‘should’ and implies that other options do exist.
You could take a taxi into town. It might be quicker.
We could go to the cinema tonight if you want.
They could meet us tomorrow.
Modal verbs for offers and invitations
We use the words ‘can’, ‘could’ and ‘shall’ to make offers. The word ‘could’ is most polite. We can also use the word ‘will’ to make an offer when we are assuming assent.
Can I help you with that?
Could I help you with that?
Could I offer you a lift?
Shall I get your coat?
Shall I give you my number?
I will give you a lift to the shop.
We use the word ‘would’ for invitations. We also use the word ‘must’ for a polite general invitation that does not always need a reply.
Would you like to go out for dinner?
Would you like a dessert?
We must do this again soon.
Modal verbs to talk about obligations
We use the word ‘must’ for obligations and necessities. If talking about a past event, this changes to ‘had to’. The word ‘ought to’ is also sometimes used for obligations. We add the word ‘not to create a negation.
You must walk on the pavement
Drivers must stop at the traffic lights
You must not talk in the library
You must be quiet in the library
They had to be quiet in the library
We had to wear smart clothes at work
Modal verbs to talk about the future
I will go to university tomorrow
I won’t go to university tomorrow
The past tense of ‘will’ is ‘would’: I would not go to the university
It would be too far to walk
I would have called you if I had arrived home in time
I would buy a car if I had enough money
If I had a car, I would be able to take more bags
What would happen if we were late?
Looking forward in time
We use the future perfect tense, which is the phrase ‘will have’ to talk about an action that will have been completed at a future time.
By this time next week, I will have already taken the exam
I will have finished five novels this week
How long will it have been since we last visited Tuscany?
It’s 6pm already, mum will have finished work by now
You will have lived in your house for 10 years this summer
Modal adjectives and adverbs give more information about the probability or the frequency of an event. Modal adjectives can be placed before the main verb to indicate the modality of the verb, that is, its probability or frequency.
Examples of modal adjectives: definite, certain, bound (informal), probable, likely, clear, possible, conceivable, unlikely, improbable, impossible
Examples of modal adverbs: definitely, certainly, probably, surely, clearly, likely, possibly, perhaps, unlikely, not possibly, inconceivably
Modal adverbs for frequency: always, often, usually, regularly, sometimes, occasionally, now and then, hardly ever, rarely, never, once in a blue moon (an idiom, meaning only very rarely)
Daily, weekly, nightly, fortnightly (once every 2 weeks), monthly, yearly / annually
Modal adjectives and adverbs in context:
Peter is a likely candidate for the job
Judy will definitely pass the exams next week
It is bound to rain tonight
It is possible that I’ll go to work tomorrow, but I have a cold so I probably won’t
John was clearly having an argument with him, so it was inconceivable that he was in a good mood
You are surely not going to run in the rain? The ground is so wet, you will probably fall over.
I never eat ice cream but I sometimes eat iced yoghurt
He occasionally walks to work but he usually drives
She always buys a black coffee when she arrives; now and then, she will buy a latte
I hardly ever play tennis – only once in a blue moon. I prefer basketball – I play in a weekly match with my club
Which modal verbs do you find the most difficult? Let us know your thoughts in the comments.