Английский грамматика.

Knowledge of set theory won't really be needed until the nal week of lectures, and
by then you should be able to complete all of the exercises.
Переведите и объясните почему используется won't

Knowledge of set theory won't really be needed until the nal week of lectures, and
by then you should be able to complete all of the exercises.

Knowledge of set theory won't really be needed until the week of lectures, and
by then you should be able to complete all of the exercises.