Everybody feels nervous before a test.
I fell asleep during the movie.
We were tired after our visit to the museum.
Don’t forget to close the window before you go out.
I often fall asleep while I’m reading.
They watched TV after they did the dishes.
We didn’t speak during the meal.
We didn’t speak while we were eating (not during we were eating)
We played basketball for two hours. (not during two hours)
I lived in Florida for a year (not during a year)
I always have breakfast before going to work. (= before I go to work)
After doing the dishes, they watched TV. (= after they did)
Before eating the apple, I washed it carefully. (not before to eat)
I started work after reading the newspaper. (not after to read)