Complete the sentences using could/couldn't or was/were able to.
1. Her grandparents were multilingual. They... speak six foreign languages.
2. Though the day was rather windy the firemen... put the fire out in less than ten minutes.
3. Linda loved sewing greatly. She... make her clothes without any help.
4. He... do this, if he tried.
5. Even though I hurt my leg I... swim back to the boat.
6. She... enter the university as she knew the material well enough.
7. ... you speak English before you went to London? — Unfortunately I... not speak it very well.
8. Doreen had a terrible sore-throat. It was very difficult for her to swallow but she... drink a cup of broth.
9. Did you buy any fresh fruit? — Oh, it was really a problem, I... buy it in the market.
10. I was sure I... get to the top of the mountain.
11. Happily Ann... swim across the river, otherwise she would have drowned.
12. As he was not interrupted he... finish his work by the evening.
13. I'm sorry but I... not come to the party on Sunday.
14. They were a long way from the stage. They... see all right but they... not hear very well.
15. The police were suspicious at first but I... convince them that we were innocent.
16. I had no key so I... not lock the door.
17. When the garage had repaired our car we... continue our journey.
18. George played tennis well but he... not beat Graham.
19. The car fell down into the river. The driver... get out but the passengers sank.
20. At five years old he... compose poems and everyone approved of them.