Exercise 13. Put the verb to be in the plural and change the sentence accordingly:
1. I am always glad to see them. 2. When is he free? — He is free in
the evenings. 3. She is so happy! 4. When is he at home? — He is at
home in the morning. 5. Who is ill? — My mother is. 6. Are you
hungry? — No, I am not. 7. Is your sister at school? — No, she isn’t.
She isn’t at school. 8. Who is away? — Petrov is away. 9. Am I right? —
Yes, you are. 10. How are you? — I’m quite well, thank you. 11. Are
you tired? — Yes, I am. 12. There is a woman in the room. 13. Who is
absent? — Ivanov is. 14. I am thirsty. 15. She is wrong.

1. We are always glad to see them. 2. When are they free? — They are free in the evenings. 3. You are so happy! 4. When are they at home? — They are at home in the morning. 5. Who are ill? — My parents are. 6. Are they hungry? — No, they are not. 7. Are your sisters at school? — No, they aren't. They aren’t at school. 8. Who are away? — Petrov ans Sidorov are away. 9. Are they right? — Yes, they are. 10. How are you? — We are quite well, thank you. 11. Are you tired? — Yes, we are. 12. There are women in the room. 13. Who are absent? — Ivanov and Petrov are. 14. Children are thirsty. 15. You are wrong.