Pop quiz

A 'pop quiz' is a quiz that a teacher gives with previous warning. Often, they are given to see who has done the homework, such as keeping up with the reading.

Example:
-How was English today?
-Horrible. We had a pop quiz and I hadn't read.

School-night

A 'school-night' is a night when there is school the next day. Sunday-Thursday are school-nights.

Example:
-Mom, can I watch tv?
-No, sweetie, it's a school-night! Time to take your bath!