as soon as连接的两个句子有什么语法规定啊

没有什么特别的规定.主要是引导时间状语从句.表示“一.就”.而且主句如果是将来时,从句用一般现在时.例如：I will wtite to you as soon as he comes back.He said he would be back as soon as he finished the project.