It is requested that Comrade Li (should) have a word at the meeting . 有人请求李同志在会上谈几句话。
It is important that we (should) unite with all that can be united in the struggle . 在斗争中团结一切可以团结的人是非常重要的。
★在含有 suggestion , order , plan , idea 等后面的表语从句和同位语从句。
My suggestion is that we (should) send a few comrades to help the other groups . 我的建议是我们派几个同志去帮助别的小组。
My idea is that we (should) challenge the other groups to a friendly competition . 我的意见是向别的组挑战，我们来一个友谊竞赛。
2 . 在下列状语从句中，要用虚拟语气。
★ 以 in order that , so that 引起的从句(谓语多用 may 或 might 加动词原形构成，在口语中也常用 can 或 could 加动词原形)。
Let\'s hand in the exercises earlier so that the teacher may have time to correct them . 让我们早点交练习以便让老师有空儿修改。
The teacher spoke slowly in order that the students could / might hear clearly . 老师说得很慢，好让学生们听得清楚些。
★ 以 lest (以免)，for fear that 和 in case 引起的从句中谓语多用“should + 动词原形”这一结构形式。
He took his umbrella with him lest it should rain . 他带了雨伞，以免下雨。
Here\'s some money in case you should need it . 这儿有些钱以防你需要用。
以 what , whatever , whoever , no matter what 三类代词或词组引起的从句中谓语多用“may + 动词原形”这一结构形式。
Come what may , we will go ahead . 不管发生什么情况，我们都要干下去。
这时如果指的是一个过去的动作，may 后面的动词就要用完成形式。
We mustn\'t be proud however much you may have achieved . 不管我们有多么大的成就，都不应该骄傲。
3 . 虚拟语气还可用在口语中，使语气显得比较委婉、客气，这时谓语动词多用“should (would , could , might) + 动词原形”这一结构形式。
★ 陈述自己的看法。
I should be glad to talk to you . 我愿意跟你谈谈。
★ 提出请求或邀请。
Would you mind shutting the door ? 劳驾把门关上。
★ 提出建议或劝告。
You\'d better leave the matter to him . 你最好把这件事交给他。
★ 提出问题。
Do you think you could spare me a few minutes ? 我能占你几分钟时间吗 ?
4 . 此外，某些表示祝愿的句子中也需要用虚拟语气，常见的有如下几类：
★ 用原形。
“Damn it , ”cursed he . 他骂道：“真混蛋!”
★ 由“may + 动词原形”构成。
Carry the revolutionary tradition forward , may you gain still greater glory !
发扬革命传统，争取更大光荣。
★ 用在 if only 引起的感叹句之中。
If only I hadn\'t lost it ! 如果没丢失它该多好!
5 . 在It\'s necessary (important , natural , strange , unusual , a pity , a shame , no wonder , etc . )that 句形中，主语从句中的谓语也常用(should) + 动词原形。
It\'s unusual that he (should) go to school so early .
It\'s necessary that Mr . Smith (should) be sent to a hospital as soon as possible .
It\'s a pity that he (should) be careless .
It\'s strange that he (should) pass the examination .
注意：在 It\'s (high) time that 句型中，从句中谓语动词常用过去式，也可以用 should + 动词原形，但 should 不能省略。
It\'s high time that we went (should go) to bed .
6. 含蓄型虚拟语气。通过介词或者介词短语 but for , with , without 和or , otherwise 来引导虚拟语气。
But for the leadership of the Party , we could not live a happy life today . = It it were not for the leadership of the Party , …