In this video, I'm going to teach you the basics about modal and semi-modal verbs.

A lot of my students ask me about how and when to use modal verbs.

I'm going to teach you the basic English grammar and the situations when you will need

to use a modal verb.

There's a lot of information in this video.

Be sure to watch until the end because there's a quiz and homework.

Let's get started.

So what is a modal verb?

Modal verbs are helping verbs or auxiliary verbs.

They give more information and more specific meaning to the main verb in a sentence.

Modal verbs can express ability, suggestion, permission, certainty, possibility.

I will briefly talk about all of these usages in this video.

Let's move on.

Let's have a look at the grammar rules of modal verbs.

I can swim very well.

'can' is our modal verb.

Modal verbs always come first before the main verb in a verb phrase.

Here's our main verb.

Here is our modal verb – 'can' comes first.

I can swim very well.

Let's look at the next sentence.

You should be more careful.

Modal verbs are followed by a bare infinitive.

This is our bare infinitive.

There is no 'to' after 'should'.

'You should to be more careful' is wrong.

'You should be more careful' is correct.

Let's have a look at the next sentence.

You have to eat quickly.

Semi-modal verbs are followed by 'to' in a sentence.

You have to eat quickly.

Hang on.

I just taught you not to use 'to'.

When you have 'should', don't use 'to'. 'should' is a modal verb.

'have to' is a semi-modal verb.

How do you know this?

Please just memorize it.

'You have to eat quickly' is correct.

Moving on.

Layla works hard.

Here we have an 's' ending.

This is correct.

Layla must work hard.

There is no 's' here.

And there is no 's' on the modal.

When we have modal verbs, we never put 's,' 'ed,' or 'ing' endings.

'Layla must work hard' is correct.

Lastly, let's look at negatives.

I eat.

I don't eat.

'don't' is our negative.

I should eat.

I should not eat.

'not' is our negative.

When we have a modal verb, we do not use 'doesn't' or 'don't' here.

We only use 'not'.

'I should not eat' is correct.

Now that we know more about the grammar of modal verbs,

let's move on and look at some more examples.

Let's take a look at some more modal verbs.

These ones express ability.

'can' and 'able to' I can dance.

'can' is our modal verb.

It shows we have an ability.

I can dance.

I can't sing.

'can't' inability.

I can't sing.

'can't' is a contraction of 'cannot'.

I'm able to swim.

'able to' 'able to' is a semi-modal verb.

We know that because 'to' is here.

I'm able to swim.

I'm not able to cook.

'able to' uses 'not' in negative form.

'I'm not able to cook' shows inability.

Let's move on some more examples.

Let's take a look at some modals that express advice and suggestions.

'should' 'shouldn't'

'ought to' 'ought not to'

You should stop smoking.

'should' is a modal that gives us advice or suggestion.

'You should stop smoking.'

Good advice.

You shouldn't drink so much.

'shouldn't' is a contraction of 'should not'.

You shouldn't drink so much.

Good advice.

You ought to prepare for the test.

'ought to' is a semi-modal.

Here's that 'to'.

You ought to prepare for the test.

A suggestion and some good advice.

You ought not to be worried.

Here's that 'not'.

The negative form.

You ought not to be worried.

Good advice.

Now, 'ought not to' is not that common, but you may hear it once in a while.

Let's move on to some more examples.

Let's look at some modal verbs that express permission.

'may' 'may not'

'can' 'can't'

'could and 'can', again.

You may leave class early.

'may' is our modal verb.

It expresses permission very politely.

Maybe your teacher will not say this.

You may leave class early.

You may not be allowed to enter.

'may not' that's our modal verb in negative.

You do not have permission to enter.

You can go home now.

We talked about 'can' and it was used for ability.

'can' is also used for permission.

You can go home now.

You have permission to go home now.

You can't come home late.

'can't' You do not have permission to come home late.

Here are some questions.

'could' 'could' is a modal verb.

Could I leave early?

We're asking for permission.

Can I help you?

Again, asking for permission.

Let's have a look at some more examples.

Let's look at a modal that expresses certainty.

'must' and 'mustn't'.

You must study English.

'must' is a very strong modal.

It expresses certainty.

You have to study English.

You have no other choice.

You must study English.

You mustn't cheat on the test.

'mustn't' is a contraction of 'must not'.

Again, it is very strong.

This is not a suggestion.

You have no other choice.

You mustn't cheat on the test.

Let's look at our next example.

Let's have a look at some modal verbs that express possibility.

'could' 'couldn't'

'might' 'might not'

'may' 'may not'

He could be smart.

It's possible.

Possible means we are not hundred percent sure.

We don't really know. That's a possibility.

He could be smart.

Maybe he's smart, maybe he's not.

He couldn't be lazy.

He couldn't.

'couldn't' is a contraction of 'could not'.

Maybe he's lazy, maybe he's not.

It's a possibility.

We don't really know.

She might be late might.

Might. It's possible.

She's going to be late but again we don't really know.

She might not be healthy.

She could be healthy, she could not be healthy.

It's a possibility.

We're not very sure.

They may be friendly.

Again, it's a possibility.

We're not sure.

They may not be quiet.

We don't really know.

It's a possibility.

Let's move on to some extra practice.

Let's do some examples together.

advice - This sentence expresses advice.

You're dirty.

You_____ take a shower.

Which modal expresses advice?

Correct. 'should' You're dirty.

You should take a shower.

inability - This example shows inability.

Sorry, I _____ help you.

Which modal expresses inability?

Well, we know 'can' expresses ability.

'can't' expresses inability.

Sorry, I can't help you.

permission - This example shows permission.

____ I give you some advice?

Which modals show us permission?

That's right.

'could' or 'can' are both modals that show permission.

Let's use 'could'.

Could I give you some advice?

certainty - You _____ be late for your final exam.

Which modal expresses certainty?

'must' You must be late for your final exam.

Wait a second.

You must not be late for your final exam.

That's correct.

possibility - She ___ be rich.

Which modals express possibility?

'could' or 'might' are both good choices.

Let's use 'might'.

She might be rich.

Great job, everyone.

Let's move on.

This was just a brief look at modal verbs.

I have a lot more information that I hope to give you in future videos.

For now, let's look at the homework.

I want you to practice using 'ought to'.

Please give me some life advice using ought to in the comments below.

Also, don't forget the quiz.

You can find the link for the quiz in the video description below.

Good luck and see you in the next video.