As if，表示与将来相反的虚拟语气，后面会用would /should/ could/ might+动词原形，举例如下:
The man looked worried as if something would happen to him.
He opened his mouth as if he would say something.
I have been working for hours， yet it still looks as if it could reach out and touch it.
特别注意:并非所有 As if从句都要用虚拟语气。从句所表示的内容，若为事实或可能为事实，就用真实语气。
It looks as if it is going to snow.
（真实语气）
It looks as if we will be late.
