Ex. 2. Write the sentences, choosing one of the modals.
1. We are leaving tonight, so you (should/must) buy a ticket for the flight.
2. (May/Might) I come in?
3. David (can/could) cook well when he wants to.
4. 'Do you think it (can/might) rain?' 'Yes, possibly. We don't want to get wet so I think we (should/must) take our raincoats.'
5. Jenny tried to carry him but she (can't/couldn't).
6. We (can/might) visit my cousin in Australia next year but we don't know yet.
7. In many countries, you (should/must) wear a seat belt in the car - it's the law.
8. (Can/May) you hold this for me, please?
9. I know they enjoy their work but they (shouldn't/mustn't) work at the weekends. It's not good for them. I think they (should/must) spend time at home with their families.
10. The letter (can/may) arrive tomorrow.

We are leaving tonight, so you must buy a ticket for the flight.
Здесь must, потому что поездка уже запланирована и билет нужен обязательно.

May I come in?
May употребляется, когда вежливо спрашивают разрешение.

David can cook well when he wants to.
Can выражает умение, способность.

“Do you think it might rain?” “Yes, possibly. We don't want to get wet so I think we should take our raincoats.”
Might — возможно, should — стоит взять, это разумно.

Jenny tried to carry him but she couldn't.
Couldn't — не смогла.

We might visit my cousin in Australia next year but we don't know yet.
Might подходит, потому что это только возможность, а не факт.

In many countries, you must wear a seat belt in the car - it's the law.
Must употребляется, когда есть правило или закон.

Can you hold this for me, please?
Can — обычная просьба.

I know they enjoy their work but they mustn't work at the weekends. It's not good for them. I think they should spend time at home with their families.
Mustn't — нельзя, should — им стоит проводить время с семьёй.

The letter may arrive tomorrow.
May выражает вероятность, возможность.