Решение:
- I was late for school yesterday. (was используется с 'I')
- She was very happy with her result. (was используется с 'She')
- They were playing in the garden in the evening. (were используется с 'They')
- He was absent last Monday. (was используется с 'He')
- We were excited about the school trip. (were используется с 'We')
- It was raining heavily last night. (was используется с 'It')
- You were my best friend in childhood. (were используется с 'You')
- The boys were tired after the match. (were используется с 'The boys' - множественное число)
- I was afraid of the dark before. (was используется с 'I')
- The cat was sleeping on the chair. (was используется с 'The cat' - единственное число)
- She and I were in the same class last year. (were используется с 'She and I' - множественное число)
- This was my favourite toy when I was small. (was используется с 'This' - единственное число)
- Those flowers were fresh in the morning. (were используется с 'Those flowers' - множественное число)
- He was very polite to the teacher. (was используется с 'He')
- We were proud of our work. (were используется с 'We')
Ответ: 1. was, 2. was, 3. were, 4. was, 5. were, 6. was, 7. were, 8. were, 9. was, 10. was, 11. were, 12. was, 13. were, 14. was, 15. were.