[英语语法手册]虚拟语气 E
省去从句或主句的虚拟结构
虚拟结构中的从句或主句有时形式上可以省略，但意义上却仍存在。
1)省去了条件从句的虚拟结构。如：
That would be fine.那就太好了。(省去了if you should do it或类似条件)
You might stay here forever.你可以永远呆在这里。(省去了if you wanted协或类似条件)
I would not have done it.我是不会做那件事的。(省去了if were you或类似条件)
[注]虚拟结构中省去的从句有时并不容易找出。如：
Who would have thought of it ? 谁会想到是这样的呢?
2)省去了结果主句的虚拟结构(常用以表示愿望)。如：
If he were here!假如他在这里该多好啊!
If I had never married.如果我从未结婚就好了。
这种结构也常用if only开头。如：
If only I could help you! 假如我能帮助你，那该是多好啊!
If only I were ten years younger!我要是能年轻十岁该多好啊!
If you would only try harder!你如再努力一试就好了。(only亦可置于would等助动词之后)
[注]有时if only只表条件，不表愿望。如：
If only I had known earlier，I'd have sent you a telegram.我只要知道得早一点，就会拍电报给你了。