As soon as是英语中常见的一个短语，意思是“一……就……”，as soon as连接的时间状语从句中，指未发生的动作，规律是：主句一般将来时，从句用一般现在时代替一般将来时。
as soon as的用法归纳总结
1、as soon as引导时间状语从句当主句用一般过去时时，从句中用一般过去时或过去完成时。
2、as soon as可以表将来的事：这时主句用一般将来时，从句用一般现在。（主将从现）
3、当主句用一般将来时时，可以用一般现在时代替一般将来时。
as soon as后面用什么时态
两种情况
1、语句表将来：主句用将来时，as soon as引导的从句用一般现在时。
2、语句表过去：主句和从句都要用过去时态。
例句
表将来：
1、I will tell him the news as soon as he comes back home.
等他回来，我就把这个消息告诉他。
2、As soon as Tony finishes his homework , he can play with us.
只要托尼完成了作业，他就可以跟我们一起玩了。
表过去：
1、He got married as soon as he graduated.
他一毕业就结婚了。
2、As soon as I told her my name, she clammed up.
我把我的名字告诉她后，她就什么也不说了。
as soon as等引导的时间状语从句介绍
as soon as意为“一……就……”，引导时间状语从句。
如：
Please call back as soon as you arrive school.请你一到学校，就给我回电。
I’ll write to you as soon as I get there.
我一到那儿就给你写信。
As soon as I went in, Tom cried out with pleasure.我一进门，汤姆就高兴的叫起来。
as soon as引导的时间状语从句前后时态搭配：
（1）主句为一般将来时，从句用一般现在时表示将来。例如：
SHe will come to my home as soon as she gets to tianjin.她一到天津就来我家。
（2）主句为一般过去时，从句也用一般过去时。
例如：
SHe took out her English book as soon as she sat down.她一坐下，就拿出她的英语书。
as soon as引｜导时间状语从句意为'一…就…'，其主从句的时态，也遵循'主将从现'原则。
e.g. I will tell you as soon as he comes back.他一回来我就告诉你。
下面的连词引导的时间状语从句，都遵循'主将从现'原则：when,while,after,as,until.
e.g. They will never let you know until it happens.
直到事情发生了，他们才会让你知道。
When I grow up, I'll be a nurse and look after the patients.
当我长大后，我要当一名护士去照顾病人。