Task 4. Underline the correct answer.

Решение:

1. James and his grandfather was watching a documentary film about whales and sea animals at half past 8 the day before yesterday. (Подлежащее "James and his grandfather" — множественное число, но глагол "was watching" согласуется с "grandfather" как с главным словом в сочетании, либо "James and his grandfather" могут рассматриваться как единое целое, действующее вместе).
2. Oliver was doing his homework while his mother and father were watching an adventure film. (Oliver – единственное число, "mother and father" – множественное число).
3. Why was she singing a lot at 9 o'clock in the evening? (She – единственное число).
4. I was listening to music yesterday evening. It was amazing. (I – единственное число).
5. What were you doing at 5 o'clock yesterday? (You – может быть единственным или множественным числом, но в Past Continuous используется "were").
6. I wasn't reading a book. I was really boring. (I – единственное число).
7. Mister Green was watching a historical film for 2 hours and 20 minutes yesterday. (Mister Green – единственное число).
8. What was your brother doing yesterday morning? (Your brother – единственное число).
9. Lenny wasn't drawing a picture from 4 to 8 o'clock yesterday. He was very tired and sleepy. He wasn't able to draw. (Lenny – единственное число).
10. Tom and Harry were doing their homework while their sisters were watching an exciting animated film. (Tom and Harry – множественное число, "their sisters" – множественное число).
11. I was cooking from 2 to 3 o'clock yesterday. (I – единственное число).

Ответ: 1. was; 2. was, were; 3. was; 4. was; 5. were; 6. wasn't; 7. was; 8. was; 9. wasn't; 10. were, were; 11. was.