【篇一】高三年級英語語法知識點
1. 定義：用作主語的從句叫做主語從句。
2. 構成：關聯(lián)詞+簡單句
3. 引導主語從句的關聯(lián)詞有三類：
(1) 從屬連詞that。 如：That they were in truth sisters was clear from the facial resemblance between them.
很明顯，她們確是親姐妹，她們的臉型很相似。
(2) 從屬連詞whether。如：
Whether he’ll come here isn’t clear. 他是否會來這里還不清楚。
(3) 連接代詞who, whom, whose, what, which, whoever, whatever, whichever
連接副詞 where, when, how, why。如：
What she did is not yet known. 她干了什么尚不清楚。
How this happened is not clear to anyone. 這事怎樣發(fā)生的，誰也不清楚。
Whoever comes is welcome. 不論誰來都歡迎。
Wherever you are is my home ---- my only home. 你所在的任何地方就是我的家----我的家。
解釋：
1. 主語從句能用it作形式上的主語。常以it作形式主語的句型有：
A. It+be+形容詞(obvious, true, natural, surprising, good, wonderful, funny, possible, likely, certain, probable, etc.)+that從句。如：
It is certain that she will do well in her exam. 毫無疑問她考試成績會很好。
It is probable that he told her everything. 很可能他把一切都告訴她了。
B. It+be+名詞詞組(no wonder, an honour, a good thing, a pity, no surprise, etc.)+that從句。如：
It’s a pity that we can’t go. 很遺憾我們不能去。
It’s no surprise that our team should have won the game. 我們沒贏這場比賽真意外。
C. It+be+過去分詞(said, reported, thought, expected, decided, announced, arranged, etc.)+that從句。如：
It is said that Mr. Green has arrived in Beijing. 據(jù)說格林先生已經到了北京。
It is reported that China has sent another man-made earth satellite into orbit.
據(jù)報道中國又成功地發(fā)射了一顆人造地球衛(wèi)星。
D. It+seem, happen等不及物動詞及短語+that從句。如：
It seems that Alice is not coming to the party at all. Alice似乎不來參加晚會。
It happened that I was out that day. 碰巧我那天外出了。
E. It+doesn’t matter (makes no difference, etc.)+連接代詞或連接副詞引起的主語從句。如：
It doesn’t matter whether she will come or not. 她是否來這無關緊要。
It makes no difference where we shall have the meeting. 我們在哪里開會毫無區(qū)別。
F. 當that引導的主語從句出現(xiàn)在疑問句中時，要以it作形式主語，而把主語從句后置。如：
Is it true that the scientist will give us a lecture next week? 下周那位科學家將給我們作報告是真的嗎?
Does it matter much that they will not come tomorrow? 他們明天不來很要緊嗎?
G. 當主語從句出現(xiàn)在感嘆句中時，要以it作形式主語，而把主語從句后置。如：
How strange it is that the children are so quiet! 孩子們這么安靜真奇怪!
2.注意連接代詞whoever, whatever, whichever等引導主語從句的含義
Whoever comes will be welcome. (whoever=the person who) 來的人將受到歡迎。
Whatever he did was right. (whatever=the thing that) 他所做的事情是正確的。
Whichever of you comes in will receive a prize. (whichever=anyone of you who) 你們當中不論哪個進來將會得到獎
【篇二】高三年級英語語法知識點
under age 未成年，未達到規(guī)定年齡
He was rejected by the army because he was under age. 他因尚未成年而被拒絕參軍。
You shouldn’t sell cigarettes to teenagers who are under age. 你不應該把香煙賣給沒未成年的青少年。
under arrest 被捕
You are under arrest in the name of the law. 你被依法逮捕了。
He was soon put [placed] under arrest. 他不久就被逮捕了。
under attack遭受攻擊
The company has come under fierce attack for its decision to close the factory. 因為決定要關閉工廠，公司受到猛烈攻擊。
under consideration 在考慮中;在研究中
The question is now under consideration. 這個問題正在考慮中。
The plan is under consideration by the Ministry of Education. 教育部正在研究這個方案。
under construction 在建造中
The new railway is under construction. 新鐵路正在修建當中。
The bridge is under construction. 這座橋正在建造中。
There are two new hotels near here under construction. 附近正在興建兩家新的旅館。
under control 在控制中
They soon got the fire under control. 他們很快把火勢控制住。
It took the teacher months to bring his class under control. 這個老師花了幾個月的時間才管住了他的班級。
under copyright 享有版權
The poem is still under copyright, so you have to pay to quote it. 該詩仍然享有版權，因此你必須支付引用費。
under cover 在隱蔽處;秘密地;在信封或郵包中
Plans for the attack were made under cover. 進攻計劃是秘密制定的。
The check came under cover in yesterday’s mail. 支票是裝在信封里和昨天的信一道寄來的。
under discussion 在討論中;在審議中
That has no relation to the matter under discussion. 那與正在討論的事無關。
That’s another topic that will come under discussion. 那是另一個要討論的問題。
under examination 在檢查中;在審查中
The prisoner was still under examination. 囚犯仍受審。
The proposals are still under examination. 提案仍在審查中。
under fire 在炮火中;被攻擊中
We were under fire from all sides. 我們遭到了來自四面八方的射擊。
The headmaster was under fire for not sending the boys home who stole the car. 校長由于沒有開除那幾個偷汽車的學生，受到責難。
under guarantee 在保修期內
It’s still under guarantee, so the manufacturer will repair it. 保證書還有效，所以廠家會給修理的。
The car is still under guarantee, so you should be able to get it repaired free of charge. 汽車還在保修期內，所以你應該可以免費修理。
under oath 在法庭上宣過誓要說實話
The judge reminded the witness that he was still under oath. 那法官提醒證人他已宣誓不作偽證。
under obligation 有義務;一定要
The one who did the damage in under obligation to pay for it. 造成損失的人有義務賠償。
【注】在現(xiàn)代英語中通常用under an [no] obligation的形式：
You’re under no obligation to pay for goods which you did not order. 沒有訂購的貨物就無須付款。
She’s under an obligation to him because he lent her money. 因為他把錢錯給她了，所以她有償還他的義務。
