or else

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

你力学习, 然话, 英语考试会及格。

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

"要碰油,否则会把你橡胶鞋弄坏。"

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

快点, 要然就来及了。

He must be teasing,or else he’s mad.

他一定是在开玩笑,然他就是疯了。

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

那但是心里话，也是魂里话；倘有虚假，让魂下地狱。