一、had开头的否定虚拟语气？
①
had是have的过去式,
否定形式：在had的后面加not,表示为had not。
Had 一般放在句首是表示虚拟,但是是倒装的用法.
比如说Had I had time, I would have done that yesterday.的原来的顺序是If I had had time,I would have done that yesterday.这里将had提前构成倒装句,句意是一样的.
②
Had开头的句子往往是对过去的虚拟条件句采用倒装的结构。
二、if从句的倒装和省略？
在if 引导的虚拟条件句中，倒装句省略if
Had he worked hard, he would have been admitted to a university.
= If he worked hard, he would have been admitted to a university
三、Not only的倒装用法？
Not only在句首，（其实，是否定词放在句首，) 这个句子才倒装。
Not only do I like this movie, but my mother likes it as well. 从句是不倒装的。
但例外的是：虚拟条件句可以倒装。
（这个不是初中学的了） 简单的例句： If he were here, we would be happy. =Were he here, we would be happy.
四、if引导的虚拟条件句例句？
1.If I were you,I would choose to work in a small town.如果我是你，我会选择在小城镇工作。
2.I recommend that you be diligent if you want to pass the exam.如果你 们想考试及格,我劝你们勤奋学习。
3.If there were no wars in the world, it would be a much better place.假如没有战争，世界会更加美好。
1.对现在情况的虚拟
条件从句中谓语动词用一般过去式，主句用“would/should/might/could+动词原形”形式，表示对现在不可能实现情况的假想。
If I were you,I would choose to work in a small town.
如果我是你，我会选择在小城镇工作。（事实上我不是你）
If I had a map now,we could easily get out of the forest.
如果现在有地图，我们能很容易地走出森林。（事实上是现在没有地图）
注意：在条件从句中，如果谓语动词是be的形式，不管主语是单数还是复数，书面语中用were,而口语中如果是单数，也可以用was,不过在if I were...中一般用were.
If the world were perfect,how could we enjoy the pleasure and comfort of being successful?
世界若完美，我们如何能尝到创造成功的快慰？
2.对过去情况的虚拟
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”形式。
If it had not been for your help yesterday,I could not have caught the bus.
如果昨天没有你的帮助，我不会赶上公交车。（事实是你昨天已经帮助了我，所以我赶上了车)
3.对将来情况的虚拟
在表示与将来事实相反的条件从句中，谓语动词可用should do,were to do或动词的过去式三种形式表示，但意义略有不同。should表示的可能性最大，动词过去式的可能性次之，were to do 的可能性最小。
If things were to be twice，all would be wise.
假如凡事都可以重新做一次，人人皆可成为聪明人。（事实是并不是所有的事都可以重新做一次
