As soon as是英語中常見的一個短語，意思是“一……就……”，as soon as連接的時間狀語從句中，指未發生的動作，規律是：主句一般將來時，從句用一般現在時代替一般將來時。
as soon as的用法歸納總結
1、as soon as引導時間狀語從句當主句用一般過去時時，從句中用一般過去時或過去完成時。
2、as soon as可以表將來的事：這時主句用一般將來時，從句用一般現在。（主將從現）
3、當主句用一般將來時時，可以用一般現在時代替一般將來時。
as soon as后面用什么時態
兩種情況
1、語句表將來：主句用將來時，as soon as引導的從句用一般現在時。
2、語句表過去：主句和從句都要用過去時態。
例句
表將來：
1、I will tell him the news as soon as he comes back home.
等他回來，我就把這個消息告訴他。
2、As soon as Tony finishes his homework , he can play with us.
只要托尼完成了作業，他就可以跟我們一起玩了。
表過去：
1、He got married as soon as he graduated.
他一畢業就結婚了。
2、As soon as I told her my name, she clammed up.
我把我的名字告訴她后，她就什么也不說了。
as soon as等引導的時間狀語從句介紹
as soon as意為“一……就……”，引導時間狀語從句。
如：
Please call back as soon as you arrive school.請你一到學校，就給我回電。
I’ll write to you as soon as I get there.
我一到那兒就給你寫信。
As soon as I went in, Tom cried out with pleasure.我一進門，湯姆就高興的叫起來。
as soon as引導的時間狀語從句前后時態搭配：
（1）主句為一般將來時，從句用一般現在時表示將來。例如：
SHe will come to my home as soon as she gets to tianjin.她一到天津就來我家。
（2）主句為一般過去時，從句也用一般過去時。
例如：
SHe took out her English book as soon as she sat down.她一坐下，就拿出她的英語書。
as soon as引｜導時間狀語從句意為'一…就…'，其主從句的時態，也遵循'主將從現'原則。
e.g. I will tell you as soon as he comes back.他一回來我就告訴你。
下面的連詞引導的時間狀語從句，都遵循'主將從現'原則：when,while,after,as,until.
e.g. They will never let you know until it happens.
直到事情發生了，他們才會讓你知道。
When I grow up, I'll be a nurse and look after the patients.
當我長大后，我要當一名護士去照顧病人。