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.
Normalment, s'havia d'anar a classe, on hi hauria un professor diligent, un professor brillant, però aquesta persona només estava en certs moments i s'havia d'anar aleshores i "aleshores" no era molta estona.