过几天的英文
01
in a few days
或者是a few days later 都是可以的。
例：
The matter will rectify itself in a few days.
那件事过几天就会变好。
I am leaving for sydney in a few days' time
过几天我要到悉尼去了。
In a few days, you will meet your baby brother.
再过几天，你就会看到你的弟弟了。
02
one of these days
总有一天（用于许诺），或许明天，有朝1日
英文讲解是within an indefinite time or at an unspecified future time（在一个不确定的时间或在将来的一个不确定的时间）
例：
Good night, old chap. I'll be over again one of these days.
晚安,老弟。我过几天还会再来的。
One of these days, said Fanny, with dismal emphasis, you'll get into trouble.
过不了几天，范尼难过地强调说，你就会遇见麻烦的。
过不了多长时间的英文表达
sooner or later
过不了多长时间，早晚
used to say that you do not know exactly when something will happen, but you are certain that it will happen
来表示你不了解某件事什么时间会发生，但你一定它会发生；早晚
●Sooner or later, it will out.
在不久后，它会逃脱出来。
●Sooner or later she's going to realize what a mistake she's made.
她早晚会意识到她有一个多么紧急的错误。