soon after 是 “不久之后,稍后”的意思。
before long 是 “不久之后, 在短时间内”的意思。
soon after 后可接名词或名词性短语。
before long 只能放在句首或句尾,不接词。
例如:
The plane developed engine trouble soon after taking off.
飞机在起飞后不久发动机就出了问题。
Before long, we were deep in conversation.
没过多久,我们便聊得很起劲了。
German interest rates will come down before long.
德国的利率水平很快就会降下来。