decline 和 downfall 有什么区别？如果难以说明的话，请教我一下例句。

They’re similar. “Decline” indicates a slower event that happens over a longer period of time that may lead to a “downfall”. For example: The city’s decline of income ultimately led to its downfall.

In other context they’re interchangeable. For example: “The downfall/decline of the Roman Empire took place over ten years.”

downfall

the loss of a person’s money, power, social position, etc.; the thing that causes this衰落；衰败；垮台；衰落（或衰败、垮台）的原因

The sex scandal finally led to his downfall.

这桩绯闻最终使他身败名裂。

decilne

to become smaller, fewer, weaker, etc.减少；下降；衰弱；衰退