Student or Learner
when I was a high school student I never asked my teacher about the format of the exams
***** NOT A TEACHER *****
If you are no longer in high school, and you are telling friends about your past experiences, I would prefer:
When I was a high school student, I would never ask my teachers about the format of the examinations.
I cannot explain why. If anyone agrees with me, would you please explain the grammar involved.