if从句时态是什么
if虚拟语气的三种时态如下:
1、对目前状况的虚拟
条件从句中谓语动词用一般过去时,主句用“would/should/might/could+动词原形”方式,表明对目前不太可能实现状况的幻想。
If I were you,I would choose to work in a small town.
假如我是你,我会选择在小城镇工作。(实际上我不会是你)
2、对过去状况的虚拟
条件从句中谓语动词用过去完成式,主语用“would/could/should/might+have+动词的过去分词”方式。
If it had not been for your help yesterday,I could not have caught the bus.
假如昨日没有你的协助,我不会赶上公交车。(客观事实是你昨日已协助了我,因此我赶上了车)
3、对未来状况的虚拟
在表明和未来客观事实反过来的条件从句中,谓语动词可用should do,were to do或者动词的过去时三种形式表明,但是意义略有不一样。should表明的可能性最大,动词过去时的可能性其次,were to do 的可能性最小。
If things were to be twice,all would be wise.
如果任何事都能从新做一次,每个人皆可变成聪明的人。(客观事实是不是全部的事都能从新做一次)