не предупредили

weren't warned

→ не
phrase Rare #32,057
weren't warned Often means that someone wasn't informed about something in advance. The subject is usually understood from context.
RU: Меня не предупредили об изменении времени.
EN: I wasn't warned about the change of time.

Вы не предупредили.

You didn't warn me.

— Фантастическая женщина (2017)

Почему вы меня не предупредили?!

Why didn't you warn me?!

— Призрак в доспехах (1995)

Неужели вас не предупредили, что надо бы воздержаться?

Surely you were warned that you should refrain?

— Елена (2011)

Вас что, не предупредили?

Didn't they warn you?

— Gentlemen of Fortune (1971)

Их не предупредили.

They were not warned.

— Властелин колец: Две крепости (2002)