Ответ

Чтобы вставить правильные формы глаголов to be в предложения, давайте разберем каждый случай: 1. Yesterday, I **was** at the library. 2. My sister **wasn't** happy about her birthday party. 3. They **were** in the same class last year. 4. The cats **were** in the garden last night. 5. We **are** excited about the vacation. 6. She **was** my best friend when we were kids. 7. The children **are** playing in the park. 8. It **was** a sunny day last Saturday. 9. Our teacher **was** very kind to us. 10. We **were** at the concert last week. 11. My parents **were** on a trip last month. 12. The books **are** on the table, but now they are gone. 13. Tom and Alice **were** at the zoo yesterday. 14. I **am** sure about the answer to that question. (not) 15. The movie **was** so interesting! 16. They **were** grateful for your help. 17. The cookies **were** delicious! 18. The flowers **are** blooming in spring. 19. You **are** right. 20. The film **wasn't** good. It **was** boring. Объяснение: - **Was/Were:** Используются для прошедшего времени. **Was** употребляется с единственными числами (я, он, она, оно), а **were** с множественными (мы, вы, они). - **Wasn't/Weren't:** Отрицательные формы, соответственно. - **Am/Are:** Используются для настоящего времени. **Am** используется только с "я", **are** с "ты", "мы", "вы", "они".