Решение:
Вставляем Was или Were в зависимости от числа подлежащего:
- Was — для ед.ч. (I, he, she, it).
- Were — для мн.ч. (we, you, they).
- I was at home last evening. (I — ед.ч.)
- The concert was very interesting. (concert — ед.ч.)
- They were at the cinema on the twentieth of March. (They — мн.ч.)
- My parents were at school on the 15th of April. (parents — мн.ч.)
- Mike and Peter were at the party last Sunday. (Mike and Peter — мн.ч.)
- We were not in France last year. (We — мн.ч.)
- It was not very cold yesterday morning. (It — ед.ч.)
- I and Kate were scared two days ago. (I and Kate — мн.ч.)
- Were you angry yesterday? (you — мн.ч.)
- My dog was hungry yesterday. (dog — ед.ч.)
- My mother was very tired on the 31st of December. (mother — ед.ч.)
Ответ: 1. was; 2. was; 3. were; 4. were; 5. were; 6. were; 7. was; 8. were; 9. Were; 10. was; 11. was.