1） 由as if, as though 勾引的办法状语从句
由as if 或as though勾引的状语从句可以用陈述语气表示可能符合事实的情形，也可以用虚拟语气表示与事实不符或与事实相反的情形。
a) 表示现在情形的虚拟用过去时。
You look as though you slept badly.
你彷佛没睡好觉。
He looks as if he were young. 看样子他彷佛很年轻。（表示不年轻了）
试比较：
He looks as if he is young. 看样子他彷佛很年轻。（他便是年轻）
The teacher treats the pupil as if he were her own child. 这位老师对待这位学生就像自己的亲生孩子一样。
Susan is walking slowly, as if she looked tired. 苏珊走得很慢，彷佛她很累似的。
He treats me as if I were a stranger. 他那样对待我，彷佛我是陌生人似的。
Why is he looking at me as though he knew me? 他为什么那样看我？像是认识我似的。
My elder sister talks to me as though she were my mother or my aunt. 我姐姐与我发言时，口气就像我妈妈或姨妈一样。
I can remember our wedding as if it were yesterday.
我们的婚礼我影象犹新，就像昨天一样。
b) 表示过去情形的虚拟用过去完成时。
I felt as if my heart had stopped.
我以为彷佛我的心都不跳了。
I felt as though we had known each other for years. 我觉得我们彷佛认识多年了。
She felt as if every drop of emotion had been squeezed from her.
她以为自己的激情彷佛已经榨尽了。
It felt as if we had reversed our roles of parent and child.
觉得就像我们父母和孩子交流了角色。
He burst into a high-pitched laugh, as though he'd said something funny.
他溘然放声大笑，彷佛讲了什么可笑的事似的。
He hesitates before leaving, almost as though he had been hoping for conversation
他离开前有些犹豫，险些像是他一贯期望能够交谈点什么。
You looked as if you'd seen a ghost. 你彷佛是见了鬼似的。
They talked as if they had been friends for years. 他们评论辩论起来就彷佛他们已是多年的朋友一样。
I remembered the whole thing as though it had happened yesterday. 我以为整件事，就好象昨天发生的一样清晰。
The girl listened as though she had been turned to stone．
那女孩谛听着，一动也不动，像已经变成了石头似的。
She behaved for all the world as if nothing unusual had happened.
看她的表现就像根本没有发生过什么大事似的。
c)表示与将来事实不符合，用would/might/could+动词原形
It looks as if it might rain. 天看上去彷佛要下雨。
He talks as if he knew everything in the world. (从句与现在事实相反)
他谈起话来彷佛他知道世间的统统似的。
He talks as if he had been to the moon. (从句与过去事实相反)
他说的彷佛他上过月球似的。
She cried as if her heart would break. (从句与将来事实相反)
她哭得心都要碎了。
2） 让步状语从句
a) 用动词原形表达虚拟语气
Though he be the President himself, he shall hear us. 纵然他是总统本人，他也得听我们讲话。
Whether he succeed or fail, it won't matter to me.无论他是成功还是失落败，都与我无关。
Whatever be the motives, we cannot forgive such behaviors.无论他这样做的动机是什么，我们不能体谅这样的行为。
b) 用may, might, would 表达虚拟语气
Come what may, he would never let her down. 不管发生什么，他决不会使她失落望。
Poor though you might be, you cannot live all your life on charity. 只管你穷, 你也不能一辈子靠救援过日子。
Try as I would, I cannot prevail upon him to follow my advice. 不管想什么办法，我都不能奉劝他按我的见地行事。
让步状语从句指事实时，从句谓语动词用陈述语气。若从句内容表示现在和将来的假设情形，从句谓语动词用虚拟语气。
Though he (should) fail, there would still be hope. 纵然他失落败了，仍有一线希望。
I should say the same thing even if he were here. 纵然他在这里，我还是要这么说。
Whether he (should) succeed or fail, we shall have to do our part.
不管他成功还是失落败，我们还是要做好自己的事。
However hard it might rain rains, we shall go there together.
不管雨下得多么大，今晚我们还是要去那里。
No matter what his social position (might) be, a man is equal in the eye of the law.
一个人不论其社会地位如何，在法律面前都是平等的。
even if/even though勾引让步状语从句时，句子主句、从句都利用虚拟语气，谓语动词形式与if勾引的虚拟条件句相同。
Nobody could save him even though Hua tuo should come here. (与将来事实相反)
纵然华佗在世也救不了他。
3） 一些目的状语从句可用虚拟语气， 可采取 should + 动词原形， 或者单独利用动词原形。 否定形式则采取 not + 动词原形。由in case, lest, for fear that ,so that及in order that勾引的目的状语从句，动词用“should + 动词原形”构造，表示忧虑或目的。此外，也可以用 would/should/could/might + 动词原形。
Please remind me of it again tomorrow in case I (should) forget.
请你来日诰日再提醒我这件事，以免我忘却。
He read the letter carefully in order that he should not miss a word.
他把信读的很仔细以便不漏掉一个单词。
She emphasized it again and again, lest he (should) forget.
她几次再三强调这一点免得他忘却。
We had a meeting and talked the matter over face to face for fear that there should be any misunderstanding. 我们开了一个会，面对面谈了这件事，以免发生任何误会.
She examined the door again for fear that a thief should come in. 她又把门检讨了一遍，以防盗贼的进入。
He read the letter carefully in order that he should not miss a word. 他把信读得很仔细以便不漏掉一个单词。
He started out earlier lest he be late. 他很早就出发了以防迟到。
He left early in order that the children would not be alone in the house. 他早早动身以免孩子们单独待在家里。
I hired a boat so that I could go fishing. 我租了一条船以便能出去钓鱼。
在in order that和so that勾引的目的状语从句中，每每用can(could)或may(might)。
I shall write down your telephone number so that I may not forget.
我要把你的电话号码记下来，以免忘却。
They worked harder than usual in order that they could finish the work ahead of time.
为了能提前完成事情，他们比往常更加努力。
We will tell you the truth so that you can judge for yourself.
我把真实情形见告你，使你能自己作出判断。
4）条件状语从句中的虚拟语气
a. if勾引的虚拟条件句
条件句有真实条件句和虚拟条件句两种。顾名思义，真实条件句表示的假设是可能发生或实现的，以是句子的主句和从句都用陈述语气。而虚拟条件句表示的假设是不可能或不大可能发生或实现的，以是句子的主句和从句都用虚拟语气。
真实条件句：If I have enough money next month, I will buy a bike.
如果下个月我有钱，我就买辆自行车。
虚拟条件句：If he were free, he would help us. 假如他有空的话，他会帮助我们的。
b.错综韶光条件句中的虚拟语气
当条件从句中的动作与主句中的动作发生的韶光不一致时，主从句中谓语动词形式要根据它所表示的韶光进行相应的调度，这便是错综韶光条件句中的虚拟语气。
举个例子：
If they had studiedhard, they could do it easily now. (这里从句动作发生在过去，主句动作发生在现在)
如果他们以前努力学习的话，现在干得就会随意马虎些了。
在一些含有虚拟语气的句子中，如果主句与从句的谓语表示不同的韶光，虚拟语气可有不同形式，即主句与从句各自按自己的韶光构成虚拟形式。例如：
If I had met him before, I could recognize him.假如我以前遇见过他，我就能认出他了。
（从句表示与过去事实相反，主句表示与现在或将来事实相反）
If we were driving at a speed of 100 Li an hour, we would have arrived there 2 hours ago. 如果我们的行车速率每小时100里，两小时以前我们就会到达那里了。
（从句与现在事实相反，主句与过去事实相反）
c.蕴藉虚拟条件句
有时虚拟条件并不通过if从句表示出来，而是通过介词短语（otherwise，or，without，but for等）、高下文或其他地方表示出来，是一种蕴藉的虚拟条件句。
But for air and water, there would be no life on the earth.
假如没有空气和水，地球上就没有生命。
With your help, we might finish the plan earlier.
假如有你的帮助，我们就可以早些完成操持。
If条件状语从句中虚拟语气规律：
与现在事实相反的虚拟条件句
If +主语 +动词过去式 ；主语+ would, should, could, might+原形动词(be的过去式用were)
If I feared death, I wouldn't be a communist.
（刘胡兰说）怕去世就不做共产党员。
If there were no air, we couldn't live.
如果没有空气，我们就不能生活。
与过去事实相反的虚拟条件句
构成
If + 主语 + 动词过去完成式；主语 + would, should, could, might+have + 过去分词
例如：
If you had come a few minutes earlier, you would have met him.
如果你早来几分钟，你就会碰上他。
If there had been no air in the tube, the result of the experiment would have been more accurate.
如果试管中没有空气，实验结果就会更精确。
与将来事实相反的虚拟条件句
构成
If + 主语+ should +原形动词；主语+would,should,could,might或were+不定式+原形动词
例如：
If he were to come tomorrow, things would be easier.
如果他来日诰日会来，事情就随意马虎办了。
If the sand should be broken up, it would give out much energy.
如果沙子能被分解，它会开释出大量的能量。
注：在表示与将来事实相反的虚拟条件句中，从句中的should有时可以省略。如：
If he make the design, he might do it in some other way.
假如他来搞这个设计，他可能用其余的方法设计。
实战剖析：
If it did， it would open up its diversity program， now focused narrowly on race and gender， and look for reporters who differ broadly by outlook， values， education， and class.
如果它能把稳这个问题的话，它就会拓展其雇员多样化项目，而目前的项目只纯挚考虑招收不同种族和性别的员工，去雇佣那些在世界不雅观、代价不雅观、教诲背景及社会阶层方面各不相同的。
解析：这是一个含有条件状语从句的复合句。If it did是条件状语从句。主句中主语是it；谓语动词有两个，分别是would open up……和look for…… 这是一个与现在事实相反的虚拟语气，从句用一样平常过去时，主句用would+动词原形open up和look for.
