1
Have you studied English before you entered the University? You have not studied English before you entered the University.
2
Have they arrived at the station by 6 o'clock.? They have not arrived at the station by 6 o’clock.
3
Had James finished reading the book by last Sunday? James had not finished reading the book by last Sunday.
4
Had I done lessons by the time you called me up? I had not done lessons by the time you called me up.
5
Had the teacher given the students their homework before the bell rang? The teacher had not given the students their homework before the bell rang.