All the time; during the whole time; from the beginning (without change).
Все время; в течении какого-то определенного времени.
I knew all along that we would win.
Jeremy has known about my problems all along.
Всё это время Джереми знал о моих проблемах.
She knew all along that we'd never agree with his plan.
You're smiling! Did you know all along that I'd give you a birthday present?