Ответ:
1. John said: «I met them at the airport yesterday.» - John said that he had met them at the airport the day before.
2. He said: «I shall come to the party if I am free tomorrow.» - He said that he would go to the party if he was free the next (the following) day.
3. She said: «I shall go to the cinema in the evening if I am not very tired.» - She said that she would go to the cinema in the evening if she wasn't very tired.
4. My mother said to me: «It will be difficult for you to get up tomorrow if you don't go to bed at once.» - My mother told me that it would be difficult for me to get up the next (the following) day, if I didn't go to bed at once.
5. Nina said: «I like music and I listen to it every evening before going to bed.» - Nina said that she liked music and she listened to it every evening before going to bed.
6. My aunt said: «I shall not be thirsty if I eat some grapes.» - My said that she wouldn't be thirsty if she ate some grapes.
7. Mother said to us: «Don't go out before I return.» - Mother asked us (said to us) not to go out before she returned.
8. My sister said: «I shall be neither hungry nor thirsty if I have a cup of tea with a sandwich.» - My sister said that she would be neither thirsty nor hungry if she had a cup of tea with a sandwich.
9. Mary said: «Don't switch on TV, Fred, I am working.» - Mary asked Fred not to switch on TV, because she was working.
10. The teacher said to us: «You will have to work hard tomorrow.» - The teacher told us that we should (would) have to work hard the next (the following) day.
11. My girl-friend said to me: «I shall not be able to go for a walk with you today, because I am very busy.» - My girl-friend told me that she wouldn't be able to go for a walk with me that day, because she was very busy.
12. She said to me: «How long are you going to stay in the country?» - She asked me how long I was going to stay in the country.
13. He said to me: «I like to go to the canteen during the break.» - He told me that he liked to go to the canteen during the break.
14. He asked me: «When will you go to the canteen?» - He asked me when I should (would) go to the canteen.
Объяснение: