Today, we are doing a lesson on modal verbs of probability in the present.

Those are words like "must", "could" and "might." So let's start the lesson.

So here is a friend of mine who is called Jane.

Now Jane, as you can see, she's talking to somebody on the telephone. She's making a telephone call.

And in fact she speaking to her friend called Sarah.

Okay? So Jane is talking to Sarah and Jane is giving advice to Sarah. Okay ?

But we can only hear what Jane is saying. We cannot hear what Sarah is saying.

So this is what Jane is saying to Sarah:

"Sarah, listen to me. You have to try to forget about this man.

You live in Manchester and he lives in London. It is too far and your lives are so different.

Stop listening to his songs because that will make you sad. You must try to make some friends.

You have a difficult job working at the hospital so try to rest on the train before work.

For the pain, take an aspirin!"

Ok, so as you can see, Jane is talking to Sarah and is giving Sarah some advice.

So, what do we know about Sarah?

Well, we know a few things now. "Sarah must be in love with a singer."

So how do we know that Sarah must be in love with a singer?

Well we can... we know that because Jane is saying that she must forget about this man.

And she also says "Stop listening to his songs because that will make you sad."

Alright? So we have proof. We have facts.

So that we know that Sarah must be in love with a singer. Okay? We can be sure.

Now we can also say "Sarah could be a doctor or nurse." Okay so we we say "could"

And this is because Jane says to Sarah: "You have a difficult job working at the hospital." Okay? "working at the hospital."

So we cannot be sure that Sarah is a doctor or a nurse. We only know that she works at the hospital.

So since we are not sure, we say "could". Sarah COULD be a doctor or nurse.

"Sarah might have a headache"

Well, look at this last sentence: Jane says "For the pain, take an aspirin!" So we know Sarah has a pain.

But we do not know what type of pain. But it is possible it is a headache. It might be a toothache as well. We are not sure.

Since we are not sure, we say "might". Sarah MIGHT have a headache.

And in the negative, we can say "Sarah can't have many friends."

Now we know this because Jane says "You must try to make some friends."

So we know Sarah doesn't know...doesn't have many friends... doesn't have any friends.

We can be sure. So since we are sure, since this is the negative, we say "can't"

"Sarah might not have a car."

Alright? It is possible she has a car.

It is possible she does NOT have a car because we know that Sarah takes the train to go to work.

But we cannot be sure Sarah does not have a car.

So because we are not sure and because this is the negative, we say "Sarah MIGHT NOT have a car." Okay?

So all of these words in red...these are all modal verbs. Okay?

So we have "must", "could" and "might"

These are the three modal verbs for probability in the affirmative.

And "must" is when we are very sure. "could" is when we are quite sure but not very sure

and "might" is when we are not sure at all.

Okay? So this is the order of certainty. So the arrow...the top of the arrow .."must" is when we are very sure and "might" - we are not sure.

And in the negative, then we have "can't" and "might not".

And when we are very sure, we use "can't and when we are not very sure, we use "might not".

So in the negative, this is the order of how sure we are okay?

So that is why these are called the modal verbs of probability.

Because they express the degree of probability. Ok?

So here, Sarah MUST be in love. We are certain. We know.

We know she is in love with a singer. So we say "must be"

But here, we are not sure at all if she has a headache. So we say "might".

Ok so let's just look at the form or structure.

So here is our example again: "Sarah could be a doctor or nurse."

And so the structure is:

We have the subject followed by the modal verb then followed by the verb.

And the verb is in the infinitive form. So here, Sarah is the subject, "could" is the modal verb and "be" is the verb in the infinitive form.

And like we said earlier, the meaning...so this means "I think it is possible that Sarah is a doctor or nurse."

Ok? And if we think it is very possible, we use "must".

If we think it is quite possible we use "could" and if we think it is not very possible, we use "might".

Okay? And in the negative we use "can't" and "might not."

Okay? So let's finish with some exercises.

So I would like you to respond to the statements or questions using the words in brackets.

Example: "I haven't slept for two days." So that is the statement. The statement is "I haven't slept for two days."

And I want you to reply.. to reply or to respond to that using these two words: "must" and "tired."

So the answer to the example would be:

"You must be tired." Okay we are certain.

Somebody who hasn't slept for two days. We can be certain...we are certain that they are tired.

So we say "You must be tired."

Question one: "My parents have a very old car."

So I'll give you just a few more seconds to think.

Ok, so the answer to this one would be:

"They can't have much money."

Ok? So this is the negative and we are quite sure that they don't have much money.

Ok? They can't have much money. We are pretty sure that they don't have much money. So we say "can't".

Question two: "David has lost his dog."

And the answer to this one:

"He could be in the garden." Ok?

So, we are not certain. We are fairly certain thats the dog is in the garden. So we say "He COULD be in the garden."

Question three: "Paul has wet hair."

And the answer here is:

"It must be raining." Ok? Paul has wet hair.

He has just come inside. We are certain that it is raining. So we say "It MUST be raining."

Question four: "Michael and Simon are always arguing."

And the answer to this question is:

"They can't be friends."

Ok? So again we are.. we have proof... we can be certain because we can see that Michael and Simon are always arguing.

So we can be certain that they are not friends. And this is the negative, so we say "They can't be friends."

Ok? So that is the last question in the exercise

and that is the end of the lesson on "modal verbs of probability"

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And here are two other of my videos which you might be interested in.

This one is a listening exercise. A listening lesson and this one is another grammar lesson on the future simple tense.

Ok? So my name is Andrew at Crown Academy of English.

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