Нужна модальные глаголы can, may, must или need. 1. i do it today: it is the last day. 2. i open the window? – no, you … (not). 3. we not take the teacher’s book. 4. we not come to school in june. there are no lessons. 5. will he come to see us? – i don’t know. he … or he … not. 6. shall i phone him today? - no, you not, he is busy, but you … phone him tomorrow. 7. i cut it without a knife? – no, you … (not), it’s dangerous. 8. you not have bought the vegetables: we have everything for dinner.9. why not you understand it? it is so easy.

1. I must do it today: it is the last day.
2. May I open the window? – No, you must not.
3. We must not take the teacher’s book.
4. We don't need to come to school in June. There are no lessons.
5. Will he come to see us? – I don’t know. He may or he may not.
6. Shall I phone him today? - No, you must not, he is busy, but you can phone him tomorrow. 7. Must (May) I cut it without a knife? – No, you must not, it’s dangerous.
8.You need not  have bought the vegetables: we have everything for dinner.
9. Why can't you understand it? It is so easy