"be alert" in German to be alert auf der Hut sein wachsam sein Detailed translations for "be alert" to be alert to be alert(also: to be on alert, to be on one's guard, to look out for squalls, to be alert for trouble) auf der Hut sein to be alert(also: to be on alert, to be alert for trouble, to be on the qui vive, to put on guard) wachsam sein