(modal; past form of can)
возможно(используется для предположений) You could be right, but we need to doublecheck everything.
Возможно, Вы и правы, но надо всё проверить.
бы(используется для вежливых просьб) Could you pass me the paper?
Вы не могли бы передать мне эту бумагу?
Синонимы
was able to
were able to
might be able to
was capable of
had the ability to
managed to
would be able to
had the capacity to