Question

It be +时间段＋before... It be+ 时间点 ＋when... It has been +时间段 ＋since...分别是什么意思“

It be +时间段＋before... It be+ 时间点 ＋when... It has been +时间段 ＋since...分别是什么意思及它们的用法？
It is three times years since they got married.与It is three times years since they be married在意思上有什么区别？It was three years before he came back form abord.是什么意思？ It won't be long before we meet again.是什么意思？

Answer 1

it be 时间段 before：在……之前已经……（多久）了
it be 时间点 before：当……事情发生时是……（时间）时候
it has been 时间段 since：自从……之后已经过了……久了
it is three times years since they got married：强调结婚这件事情；他们结婚已经三年了。
it is three times years since they be married：强调结婚的状态；他们已经结婚三年了/他们已经做了三年夫妻了。
it was three years before he came back from abord：在他从海外回来之前已经过去三年了/三年过去了他才从海外回来。
it won't be long before we meet again：到我们下一次相遇不会太久的/我们很快就会再见了。