具体用法：
1、指未发生的动作。时态规律是“主将从现”，即主句用一般将来时，从句用一般现在时代替一般将来时。
I’ll tell him the plan as soon as I see him.
我一看到他就告诉他这个计划。
He’ll go home as soon as he finishes his work.
他一完成工作就回家。
I’ll write you as soon as I get there.
我一读完就把书还回去。
2、如果强调过去发生的两个动作有先后关系，从句谓语动词可以用过去完成时。例如：
As soon as they (had) returned from London, they drove to see their sick aunt.
他们一从伦敦回来，就开车去看望他们患病的姨妈。
After left as soon as he had drunk his coffee.
Andrew一喝完咖啡就走了。