I won't leave here unless you let me go.
除非你让我离开否则我是不会离开这的。
I won't buy that expensive watch unless it's at a discount.
除非它打折否则我是不会买那么贵的表的。
I won't forgive you unless you promise not to do that again.
除非你向我保证再也不那么做了否则我不会原谅你。