英语语法：用虚拟语气情况

英语自学网

　　可以引起与事实相反的方式状语从句，用虚拟语气
        　　由as if、as though引起的与事实相反的句子，不论主句的谓语是现在时或者说过去时，其谓语表示的时间概念和句子结构，都基本上与wish后的宾语从句相同。例：
        　　John pretends as if he didn't know the thing at all, but in fact he knows it very well.
        　　(用过去式表示与现在事实相反的假设)
        　　The old man looked at the picture, he felt as though he had gone back to time 20 years ago.
        　　(用过去完成式表示与过去相反的事实)
        　　They talked and talked as if they would never meet again (would+动词原形，表示与将来事实相反)