It used to be that you had to go to a classroom, and there would be some diligent teacher -- some genius teacher in there -- but that person was only in there at certain times and you had to go then, and then was not most times.
Antes, você entrava numa classe, e lá havia um professor diligente, um professor genial, mas aquela pessoa só estava presente algumas vezes e você tinha que ir, e não era a maior parte do tempo.