1, Mike shouldn't ride his motorbike to school.
2. We shouldn't watch that film.
3. They shouldn't  come that dangerous place.
4. Phong and his friends shouldn't play soccer in the park.
5. Your uncle shouldn't smoke a lot.
6. He shouldn't step on grass.

(Đổi sang thể phủ định cần thêm not là được rồi nhé 
Ví dụ : should not -> shouldn't)