Expressing obligation, ability, advice, permission

You can do all that with the use of modal verbs. We can express strong obligation or prohibition with must – mustn’t (I must go now, I’m very late. You must start exercising if you want to be healthier. You mustn’t mix that, it can cause an explosion.). Mild obligation is expressed with the correct form of the verb have to (I have to go to a meeting this afternoon. She has to get up early to get to work on time. Next week they will have to work long hours to fulfil all the orders. She had to recharge her mobile this morning as the battery went dead. Mike doesn’t have to commute to the factory as he lives five minutes away.).

We express ability with can – can’t, could – couldn’t, be able to (I can speak English but I can’t speak French. When she was only two, she could swim like a fish. When I finish this book, I will be able to speak English much better.) Can, could are besides may, might (which are also used to express possibility) also used for permission (Can I use your computer for a while, mine has crashed? Could she attend the meeting? May I borrow your car? I may be able to help you.). To express advice and sometimes criticism should is used (You shouldn’t touch that, it can kill you! She should go home and stay in bed if she’s ill. If you wanted to pass the test, you should have studied more!).

 

Activity 1. Complete these sentences with the correct modal verbs:

1. We will have to go to school by bus as we seem to have car trouble.

2. I’m really up to my eyes today. I wonder if I ……… call you back tomorrow.

3. €300,000! You ……… be right. It ……… be a mistake.

4. Give me ten minutes. I’ll call you back. We ……… be able to send you the shipment today.

5. You ……… think twice before making accusations!

6. We ……… all open our eyes and pay more attention to the dangers around us.

7. I’m sorry but I ……… help you anymore.

8. Each member of a team ……… do their share of work.

9. Be careful, the floor is slippery, you ……… slip and break an arm or leg or even worse. ……… I have a beer, please?

10. If I want to earn some holiday money, I ……… work overtime.

11. ……… you ……… go now? It’s running late.

12. Look, you seem ill to me. I think you ……… go home early today.

13. You ……… use a metal ladder here. You ……… get killed.

14. It’s easy to do that and you ……… spend a lot of money.

15. You ……… leave any machine running if there’s no one present.

16. We ……… stay at work all night yesterday as we had so many urgent orders.

 

Activity 2. Two friends are discussing what is allowed to carry on the plane. Complete the dialogue with the missing modal verbs:

Pete: Can I bring this laptop on board?

Jack: Yes, but I’m afraid you ……… take those scissors with you.

Pete: ……… I pack this camera in my suitcase?

Jack: No, you ………. You ……… take it in your hand luggage.

Pete: Do I ……… leave the knife in my suitcase?

Jack: Yes, of course, you ……… carry anything sharp on board of the plane.

Pete: What about an umbrella?

Jack: You ……… worry about an umbrella. It is allowed to have one in your carryon luggage.

Pete: And finally, what about drinks?

Jack: Liquids are only allowed if they are less than 100 ml. You ……… buy something to drink either after you pass the security controls or on the plane.

Pete: Thanks so much. You’ve really been very helpful.