or else

Make haste, or (else) you'll be late.

快点, 要不然就来不了。

"Keep off oil, or else it will perish your rubber boots."

"不要碰油,否则会把你橡胶鞋弄坏。"

You must study harder (or) else you'll fail in the English examination.

你必须努力学习, 不然, 英语考试不会格。

And from my soul too; Or else beshrew them both.

那不但里，也灵魂里；倘有虚假，让灵魂下地狱。

He must be teasing,or else he’s mad.

他一定在开玩笑,不然他就疯了。