as soon as兩種用法：

　　1、指未發(fā)生的動(dòng)作，規(guī)律是：主句一般將來時(shí)，從句用一般現(xiàn)在時(shí)代替一般將來時(shí)

　　如：I will tell him the news as soon as he comes back。

　　注：有時(shí)，為了特意表達(dá)剛剛完成某事就如何如何，需要用現(xiàn)在完成時(shí)。

　　如：I will go with you as soon as I have washed my face.

　　2、指緊接著發(fā)生的兩個(gè)短動(dòng)作，主從句都用一般過去時(shí)

　　如 He took out his English books as soon as he sat down

　　不過，我也見過從句和主句都用一般現(xiàn)在時(shí)的情況。

　　如：As soon as he finishes his classwork, he runs out of the class. 他一做完課堂作業(yè)，就跑出了教室。

　　總之，記住那兩種基本的情況，不把時(shí)態(tài)用得太混亂了就行了（比如后面從句里用了將來時(shí)，就絕對(duì)允許了）。