Ответ:

1. Why is she late?

2. I'm not on the train.

3. They are British.

4. We are not students.

5. Who are they?

6.He is a lawyer.

7. Is he asleep?

8. Is it dark outside?

9. I am here.

10. She isn't in the cafe'.

Объяснение:

Формы to be в Present Simple:

I - am

you, we, they - are

he, she, it - is

Чтобы составить отрицание после to be в нужной форме ставим отрицательную частицу not - am not, is not, are not.

Чаще используют краткую форму отрицания - isn't, aren't. У "am" краткой формы отрицания нет.