Please help me!!!

Утворіть питальне і заперечне речення.
Наприклад: I have been there very often- Nave I been there very often? I have not been there very often.

1. The snudents have passed all their exams.
2. They have answered all the questions.
3.You have solved the problem .
4. Something has happened to your friend.

1 have the students passed all their exams? The students haven't passed all their exams 2 have they answered all the questions? They haven't answered all the questions 3 have you solved the problem? You haven't solved the problem 4 has something happened to your friend? Something hasn't happened to your friend