Modals 3 - B1

certainty and possibility; ability

Look at these photos of two ordinary objects. What are they?

You are going to hear part of a quiz programme. Were you correct?

Listen again and complete these sentences.

When we’re sure something is true, we use must:

It must be a pen because that looks like ink.

They must be at home because the light is on.

When we think something is possible, we use might/could/may

It could be a butterfly because those are its wings.

He might be her brother but I’m not sure.

When we’re sure something isn’t true, we use can’t:

It can’t be a butterfly because it hasn’t got a body. (not It mustn’t be a butterfly.)

That can’t be Sue’s car because hers is at the garage.

Note:

We also use might/could/may when we are uncertain about the future:

I may go to Greece next month. (= it’s possible but I’m not certain)

My football team might win the cup.

I can = I know how to do something or it is possible for me to do something.

+ The children can swim but they can’t dive yet.

+ I can help you on Monday but not on Tuesday.

– I can’t decide what it is.

? Can you say what’s in your photo?

In the present we use can (a modal verb) or be able to (not a modal verb).

My grandfather is able to cook his own meals but he isn’t able to walk to the shops.

I’m not able to answer that question.

Note: Be able to is less common

In the past we use could or was able to:

He could / was able to walk when he was one.

The athletes couldn’t/weren’t able to train because the weather was bad.

For all other forms, we use be able to:

Future: Team A will be able to come back next week.

Present perfect: Team A hasn’t been able to answer the question yet.

Infinitive: Team A hopes to be able to come back next week.

We also use can and could for permission, offers and requests. See lesson Modals 1