3.虚拟语气用于表语从句、同位语从句
作advice,idea,order,demand,plan,proposal,suggestion,request等名词的表语从句和同位语从句,其谓语动词要用虚拟语气的结构"(should)+动词原形"。例如:
We all aGREed to his suggestion that we(should)go to Beijing for sightseeing.
My idea is that he (should)do exercises first.
4.虚拟语气用于以as if(as though)引导的表语从句或状语从句
如果从句表示与现在事实相反,谓语动词用一般过去时;表示与过去事实相反,谓语动词用"had+过去分词";表示与将来事实相反,谓语动词用"would(might,could)+动词原形"。例如:
He looked at me as if I were mad.
He speaks English so fluently as if he had studied English in England.
It looks as if it might rain.
但as if(as though)后的从句也常用陈述语气,这是因为从句中的情况往往是可能发生的或可能被设想为真实的。例如:
It looks as if our side is going to win.
5.虚拟语气用于主语从句
在主语从句中,谓语动词的虚拟语气结构用"should+动词原形"的结构,表示惊奇、不相信、惋惜、理应如此等。例如:
It is necessary(important,natural,de-sirable,advisable,strange,etc.)that we should clean the room every day.
It was a pity(a shame,no wonder,etc.)that you should be so careless.
It will be desired(suggested,decided,ordered,requested,proposed,etc.)that she should finish her homework this afternoon.
在上述三种主语从句中,should意为"应该"、"竟然",可以省去,但不可换用would。主句所用动词的时态不限。
注意:这种从句表示的是事实。如果说话人对这种事实表示惊奇,就可用虚拟语气。反之,如果不表示惊奇,that从句也可用陈述语气。例如:
It is strange that he did not come yesterday.
It is a pity that you can't swim.
