① 虚拟现在时表示与现在事实相反的假设,其if 从句的谓语形式用动词的过去式(be 一般用were),主句用would/ should/ could/ might +动词原形,例如:If I were in your position I would marry her. ② 虚拟过去时是表示与过去事实相反的假设,if 从句的谓语形式用过去完成时即had+过去分词,主句用would / should / could / might + have +过去分词,例如:If it had not rained so hard yesterday we could have played tennis. ③ 大多数的虚拟条件句属于上面三种情况的一种,但