楼主,你说的是不是
虚拟语气呀?
含有if条件句的虚拟语气的构成如下:
1) 对现在虚拟: 条件句:
一般过去时, 主句:could/would/should/ought to/might+动词原形
例:if he were here now, we could have a meeting. 如果现在他在这儿,我们就可以开会了。(注意用的是he were。he was也可以,不过虚拟语气里
be动词规范的用法还是多以were的形式出现 )
2)对过去虚拟: 条件句:
过去完成时,主句:could/would/should/ought to/might have done
例: if he had taken my advice, he shouldn't have failed in the exam. 如果他听从我的建议,他考试就不会不及格。
3)对将来虚拟: 条件句:(1)were to do (2) should do (3)一般过去时 主句:could/would/should/ought to/might +动词原形
例: If i had time/were to have time/should have time, I would visit my parents tomorrow. 如果我明天有时间,我就去看望我的父母