That she is sixty years old is unbelievable.
That she said yes is not surprising.
What he said is not true.
What she does is none of my business.
Why she is absent is still unknown.
1. 连词：that（不用翻译），whether 是否
That I am your father can’t be changed.
That he has no interest in art is obvious.
Whether she will respond to my letter remains unknown.
Whether he has betrayed us needs to be found out.
2. 代词：who 谁, what什么, which哪个, whose 谁的
Who will be the next pope hasn’t been decided yet.
What caused the fire is still a mystery.
Which (book) he chooses is unknown.
Whose (design) she likes doesn’t matter.
3.副词：when何时, where何地, why为何, how如何
When the wedding will take place depends on you. 婚礼何时举行取决于你。
Where the football game will be held is not clear. 尚不清楚将在何处举行足球赛。
Why she does it doesn’t concern me. 她做这事的原因与我无关。
How the machine works is still not fully understood. 这台机器到底是如何运转的仍未被完全弄清楚。
4.复合词：whatever无论什么、任何事、 任何东西, whoever无论谁、任何人
Whatever he has is hers. 他拥有的一切都是她的。
Whatever she says is right. 无论她说什么都是对的。
Whoever comes inside the shop will receive a present. 无论谁进店都有礼。
Whoever solves the problem will be awarded the prize. 无论谁解决这个问题将会获得奖赏。
主语从句的时态不受主句的时态的限制，根据语境实际情况而定，主句从句的语序为陈述语序，即：引导词 + 陈述语序。
That she didn’t come doesn’t surprise me. 她没来，我不觉得吃惊。
Whether it will rain tomorrow remains unknown. 明天是否会下雨，仍未知。
What killed the man is uncertain. 不确定是什么杀了这位男士。
When this happened is still in dispute. 仍在争论这事是何时发生的。
Why she married him is beyond me. 我无法理解她为何要嫁给他。
Who will speak on behalf of the company has been decided by the President. 总裁已经决定由谁来代表公司发言。
It is certain that they will attend the banquet. 肯定的是，他们会参加宴会。
形式主语 谓语 真正主语
= That they will attend the banquet is certain.
It + be + 形容词 + that …
该形容词通常为：certain，essential, fair, funny，good，important, natural，necessary, likely， obvious，possible，probable，surprising，true，vital, wonderful…等等
It is true that she is not easily persuaded. 她很难被说服，这是事实。
It is possible that the bank has made a mistake. 有可能银行出错了。
It is very likely that the same problem will occur again. 很有可能，同个问题还会再发生。
It is strange that nobody told me about this before. 奇怪的是，之前没有人向我提起过这事。
It is important that you should get things done as soon as possible. 重要的是，你尽快处理好事情。
2）It + be + 名词词组 + that …
该名词词组通常为：an honor，a good thing，a pity，a shame, a fact, a wonder, no wonder， no surprise，good news, common knowledge…等等
It was a pity that you couldn’t go. 可惜的是，你不能去。
It is a fact that I don’t like politics. 我不喜欢政治是事实。
It is good news that he is getting better. 好消息是，他渐渐好起来了。
It is no wonder that you are tired. You’ve been working for hours. 难怪你累了，你已经工作几小时了。
It is common knowledge that fish can't live without water. 鱼离不开水是常识。
3）It + be + 过去分词 + that …
该过去分词通常为：announced，arranged，believed, decided，demanded, discussed, estimated, expected，found, hoped, noted, proved, reported，required, said，suggested, thought，made clear, well known,…等等
It is said that Joe has left. 据说乔伊已经离开了。
It is believed that health is above wealth. 大家都相信健康重于财富。
It is estimated that the cup is 5000 years old. 据估计，这杯子有5000年的历史了。
It is found that there was no such thing. 经查无此事。
It is well known that the drug has no harmful side effect. 众所周知的是，这药没有不良副作用。
4）It + 不及物动词 + that …
该过去分词通常为：appear, follow, happen, occur, seem, turn out,…等等
It appears that the meeting is over. 似乎会议结束了。
It follows that she is the murderer. 由此可见，她就是杀人犯。
It seems that you have read the book. 似乎你已经读过这本书了。
It happens that she is my brother’s friend. 碰巧她是我兄弟的朋友。
It turned out that I am right. 结果表明我是对的。
It doesn’t matter that… …是无关紧要的
It makes no difference that….. ….是毫无区别的，是不重要的
It doesn’t make much difference that …是关系不大的
It is of little consequence that …是无关紧要的
It suddenly strikes me that 突然想到…
It suddenly occurs to me that 突然想到…
It doesn’t matter that we make mistakes. 我们犯错误没关系。
It makes no difference that/It doesn’t make any difference that you are one of the top students in my class. 即使你是我的班里的其中一个优等生也是一样的（不会得到特殊待遇）。
It is of little consequence that they have to find a new place to live. 他们要找一个新的住处是没关系的。
It suddenly strikes/occurs to me that we can deal with the problem in a simpler way. 我突然想到我们可以用更简单的方法来解决这个问题。
What she needs is a vacation. 她需要的是度度假。
What you should do is (to) study hard. 你该做的是努力学习。
What I enjoyed most was your performance. 我最喜欢的是你的表演。
Whether he needs a loan is up to him. 他是否需要贷款取决于她。
It doesn’t matter +代词或副词引导的从句 …是无关紧要的
It makes no difference +代词或副词引导的从句 ….是毫无区别的，是不重要的
It doesn’t make much difference +代词或副词引导的从句…是关系不大的
It is of little consequence +代词或副词引导的从句 …是无关紧要的
It doesn’t matter who will be our boss. 谁当我们的老板都没关系。
It makes no difference whether you believe me or not. 无论你是否相信我都无所谓。
It doesn’t make much difference how you look. 你长的如何都没什么关系。
It doesn’t make any difference how much you want. 你要多少都没关系。
It is of little consequence who really gained the victory. 到底是谁赢了都无所谓。
It happens/occurs…./appears that…
It is believed/said……/reported that…
It doesn’t matter + 引导词 …..
It appears that she has changed her mind. 她貌似已经改变主意。
It is reported that ten people were injured in the fire. 据报道，有十人在火灾中受伤。
It doesn’t matter why he broke up with you. 他与你分手的理由不重要。
Is it possible that we pay you in cash? 我们给你支付现金可以吗？
Is it likely that criminals will repent for their crimes? 罪犯会为他们犯下的罪行而忏悔，这很有可能吗？
How strange it is that the students are so quiet! 学生这么安静，真是奇怪啊！
How unbelievable it is that we have finished our assignment in such a short time! 我们在如此短的时间里完成了任务，真是难以置信啊！
It is uncertain if the invention can be patented. 不确定这发明能否被授予专利。
It is uncertain if they can compete with strong teams. 不确定他们能否与强队竞争。
谓语动词用： “（should） + 动词原形”，should可以省略
It + be + advisable/ critical/ crucial/ desirable/ essential/ imperative/ important / inevitable/…/ necessary/ urgent + that
It is advisable that they (should) make reservations in advance. 建议他们提前预定。
It is essential that she (should) be at the meeting. 她有必要出席会议。
It is imperative that we should act at once. 我们有必要马上行动。
It is important that we should make full use of our time. 我们充分利用时间是重要的。
It + be + decided/ desired/ ordered/ proposed/ recommended/ requested/ suggested/ …/ settled+ that
It is suggested that the meeting should be canceled. 建议取消会议。
It is recommended that you should buy a new computer. 建议你买一台新的电脑。
It is decided that we should tell her the news. 已经决定了，我们要告诉她这个消息。
It is desired that they should get everything ready as soon as possible. 希望他们能尽快准备好一切。
9. 主语从句还可用虚拟语气突出说话人强烈的情感，通常有“居然”“竟然”之意, 谓语动词：should + 动词原形， 此时的should通常不省略；若不突出强烈的情感，可不用虚拟语气
It is a pity/a shame that…;
It is amazing/astonishing/ incredible /strange/surprising that
It is a pity that you should be so biased. 真是遗憾，你居然这么有偏见。
It is a pity that you are so biased. 真遗憾，你这么有偏见。
It is strange that she should be so late. 她居然如此晚到，真是奇怪。
It is strange that she is so late. 她这么晚到，真是奇怪。