MODAL VERBS – What are they? How do we use Modal Verbs?

1. There are only ten Modal Verbs.

2. Modal Verbs are easy to use.

3. Modal Verbs are very useful.

“You should only eat eggs laid by free-range chickens. Chickens should not have to spend their lives in cages.”
Photo by Erol Ahmed on

1. There are only ten Modal Verbs:

*will,  *shall,  *might,  *may,  must,  can, could, would,  *should,  *ought to
♦ ♦ ♦ ♦ ♦

*Some of these Modal Verbs have similar meanings:

Shall is similar to will. Shall can only be used with subjects ‘I’ and ‘We’.
Shall is more formal and not as common.
♦ I’m afraid that I shall not be able to attend the wedding.
Shall we dance?

Might and may have the same meaning when talking about possibility.
♦ We might need to buy more beer for the party.
 ♦ We may need to buy more beer for the party.   

In the past, may was used for permission,
♦ May I leave the room, please?
but this is unusual now. We usually ask,
Can I leave the room, please?

Should and ought to have the same meaning.
♦ You ought to have known better!
♦ You should  have known better!
You never need to use ought to but it’s good to know what it means if you hear or see it.

2. Modal Verbs are easy to use. The rules are simple.

Modal verbs are always followed by a Base Infinitive (except when they are used for a short answer – Yes, I can. No, I shouldn’t. etc)  For example:

Infinitives with TO Base Infinitives  
To be

To go

To make

To take

To try

To learn

To buy








I should be more careful about what I eat.

I might go to the cinema this weekend.

John could make more money if he worked harder.

I would take a holiday if I needed one.

You must try a little harder if you want to impress me.

Will Maria ever learn all this grammar?

People can buy eggs laid by free-range chickens in most supermarkets.

To make a negative statement, simply put ‘not’ or ‘never’ after the Modal Verb.

Modal verb not, never Base Infinitive
He should

I might

I could

I would

I will

You must









eat so much fast food.

go to the party.

surf like Mick Fanning!

be able to punch a shark like Mick Fanning did!

swim outside the flags. ≈≈≈  

forget what I have told you!

have to spend their lives in cages.

I would never take such a risk!…… Photo by Casey Horner on Unsplash

3. Modal Verbs are very useful.

∗ Modals tell us about the speaker’s  mood  or opinions. (mood = modal)

(∗ The twelve tenses tell us about facts, or actions – now, in the past, or what we think will happen, in the future.)

Have a look at the photo above of a tight-rope walker and then at the following use of modals. See how they provide information about the speaker’s opinions and feelings, not facts or actions.

♦  He might have fallen!  / He could have fallen!

♦ He must have been scared.

♦ He must be an idiot or a hero, or both!

♦ No-one should take such risks.

♦ His family would be furious if they knew.

♦ He will have an accident one day!

None of the above sentences are about facts or real time. We don’t know that those things are actually happening, have happened or will happen.

Only the last sentence ∼ He will have an accident one day! ∼ uses one of the twelve tenses: Future Simple – will have. When you think about it, the future is not real, is it? We know the past happened, we have the present, but the future is about predictions, promises, spontaneous decisions, and schedules, all of which may or may not result in action or fact.

However, we all need a way to talk about the future and we know it’s not real yet. In English, we use WILL for future predictions, promises and spontaneous decisions.

The following sentences provide information about real facts and describe actions by using some of the twelve tenses. Unlike with Modal Verbs, we have no idea how the speaker feels or what his/her opinion is. These are simply the facts.


♦  He didn’t fall.                                  

♦ He wasn’t scared.

♦ He is never scared.

♦ He has often taken risks.

♦ He is always taking risks.

♦ His family don’t approve of his lifestyle.

♦ He loves his life.

Features of Modal Verbs

♥ They never change their form (spelling). How good is that!
NO subject  + verb agreement.        NO 3rd person ‘S’.        NO ‘ed’.        NO ‘ing’. 

♥ They are always followed by a Base Infinitive. See above notes. 

♥ They express the speaker’s opinion or feelings about:

possibility We might go the party.
obligation I must not forget to renew my passport! 

You must obey the speed limit.
(Government rules often omit ‘must’. They simply have a picture of an infringement to show a rule or law that ‘must’ be obeyed.)

prohibition You cannot smoke here.  
necessity While on holiday, they must take malaria pills every day.
ability He’s only three but he can swim really well!

He has been training for years for the Olympic Games. He must  be determined.

You can‘t possibly be tired! You’ve just been on a month-long cruise! You would have had plenty of rest!

At work: Oh no! Where’s my lunch? It’s not in my bag. I prepared it last night. I must have left it at home! I could have left it on the kitchen bench or my husband might have taken it by mistake.

The Modal ‘must’ is quite interesting in that English students often think that ‘must’ is only used for prohibition and obligation. However, native speakers rarely say ‘ You must … ‘ Instead, we say ‘You need to … ‘ and ‘You should …’ For example, I don’t say to my students, “You must watch the news tonight, or, You must do your homework.” I say something like, ” You really need to do revision if you want to remember what you’ve learnt today. If you want to improve your listening skills, you should watch the news.”

The most common way we use the Modal Verb ‘must’ is for speculating: saying what we believe is or was or has been true, as in the examples above.

I’m pretty sure it must have rained the day before you came.

There is a song by ABBA which perfectly demonstrates how we use ‘must’ for speculation. The song, ‘The Day Before You Came’, is entirely about how the singer remembers her past. In particular, she thinks about how boring and predictable her life was before she met her lover. She knows that she followed the same routines every day, so she sings:


I must have left my house at eight because I always do.

I must have read the morning paper going into town (on the train).

I’m pretty sure it must have rained the day before you came.

She believes that she is reporting facts about her life. However, perhaps one day she fell asleep in the train and didn’t read the morning paper. Perhaps one day her watch was wrong and she left her house at five minutes past eight.

When we are reporting past facts, we use past Tenses which are real. Of course, we can’t remember every little detail about our pasts, so we say what we believe must have happened, or what would have happened, or what might have happened, or what could  have happened. We use Modal Verbs!

Click on the video below to watch and listen to this very helpful song! I hope you enjoy it enough to listen a few times so that you will remember the structure: 

Modal + have + past participle

For more information and practice exercises on Modals for Speculation click here and here.

For the song lyrics with the Modal Verbs of deduction highlighted:

The Day Before You Came  by ABBA

I must have left my house at eight, because I always do.
My train, I’m certain, left the station just when it was due.
I must have read the morning paper going into town
And having gotten through the editorial, no doubt I must have frowned.
I must have made my desk around a quarter after nine
With letters to be read, and heaps of papers waiting to be signed.
I must have gone to lunch at half past twelve or so,
The usual place, the usual bunch,
And still on top of this I’m pretty sure it must have rained
The day before you came.

I must have lit my seventh cigarette at half past two
And at the time I never even noticed I was blue.
I must have kept on dragging through the business of the day.
Without really knowing anything, I hid a part of me away.
At five, I must have left; there’s no exception to the rule.
A matter of routine, I’ve done it ever since I finished school.
The train back home again,
Undoubtedly I must have read the evening paper then.
Oh yes, I’m sure my life was well within it’s usual frame
The day before you came.

I must have opened my front door at eight o’clock or so
And stopped along the way to buy some Chinese food to go.
I’m sure I had my dinner watching something on TV.
There’s not, I think, a single episode of Dallas that I didn’t see.
I must have gone to bed around a quarter after ten.
I need a lot of sleep, and so I like to be in bed by then.
I must have read a while
The latest one by Marilyn French or something in that style.
It’s funny, but I had no sense of living without aim
The day before you came.

And turning out the light,
I must have yawned and cuddled up for yet another night
And rattling on the roof I must have heard the sound of rain
The day before you came.

♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ 

This entry was posted in Grammar, Intermediate (Level 4), Pre-Intermediate (Level 3). Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.