You should not have crossed the street when the lights are red.
You should cross the street when the lights are green.
You should cross the street by the subway.
You should take off your hat when entering a room.
You should have helped your classmate to clean the classroom.
You should take some medicine.
You need not have bought bread.
You should have been present at the meeting.
You need not have sent an e-mail.
You should not have gone out without your coat.
You need not have apologized.
You should have attended this lecture.
You need not have got up at six o’clock on Sunday morning.
You should not have read till two o’clock in the morning.
You need not have copied the whole text into your exercise book.
You need not have watered the plants.
You should have returned the books to the library.