Давайте разберем каждое предложение и правильно поставим глагол to be в нужной форме. Глагол to be имеет три формы в настоящем времени: am, is и are. Используем их в зависимости от подлежащего.

1. 1) ... you are lesson now? -No, we.. We.. at the cinema.
   • Правильный вариант: "Are you having a lesson now? - No, we are not. We are at the cinema."
2. 2) The Maths home task ... very difficult.
   • Правильный вариант: "The Maths home task is very difficult."
3. 3) The children ... in the schoolyard playing football.
   • Правильный вариант: "The children are in the schoolyard playing football."
4. 4) ... Sofia in the hospital? - Yes, she ... She ... ill.
   • Правильный вариант: "Is Sofia in the hospital? - Yes, she is. She is ill."
5. 5) They ... able students. They ... especially good at Literature.
   • Правильный вариант: "They are able students. They are especially good at Literature."
6. 6) ... I happy to have a new book as a present? Yes, I .. I love reading!
   • Правильный вариант: "Am I happy to have a new book as a present? Yes, I am. I love reading!"
7. 7) The banks ... closed after 7 o'clock.
   • Правильный вариант: "The banks are closed after 7 o'clock."
8. 8) ...you a musician? -No, I ... I ... a designer.
   • Правильный вариант: "Are you a musician? - No, I am not. I am a designer."
9. 9) They ... not good friends, they .. acquaintances.
   • Правильный вариант: "They are not good friends, they are acquaintances."

Теперь вы видите, как правильно использовать глагол to be в различных предложениях. Обратите внимание на то, что форма глагола зависит от подлежащего и времени.