高中英語的語法知識總結(jié)
關(guān)于任何事物的知識都有五個層次或者要素：事物的名稱、定義、形象，有關(guān)事物的智識或者知識，以及事物本身——這才是知識的真正目標(biāo)。下面小編給大家分享一些高中英語的語法知識總結(jié)，希望能夠幫助大家，歡迎閱讀!
高中英語的語法知識1
倒裝句語法知識點(diǎn)
疑問句和特殊疑問句要倒裝
Are you cold?
Does he go to school by bike?
注意：若疑問詞在句中作主語或主語的定語時，不倒裝。
Who is your English teacher?
Whose father is a worker?
There be 句型
在There+助動詞/情態(tài)動詞+be+主語+地點(diǎn)/時間的句型中，主語在謂語be動詞后面，因此這是倒裝。
There is a mobile phone and some books on the desk.
桌上有一個手機(jī)和一些書。
There are thousands of people gathering on the square.
廣場上聚集著成千上萬的人
注意 ：引導(dǎo)詞there 還可以接appear,exist, lie, remain, seem, stand, live 等詞。
There lived an old fisherman in the village.
村里住著一位老漁夫。
There stand two white houses by the river.
河濱矗立著兩座白房子。
There existed some doubt among the students.
學(xué)生中有些懷疑。
直接引語在句首
“May I come in and take a rest?” asked the poor girl.
“Get out of the room!” shouted the angry woman.
虛擬條件句的倒裝
當(dāng)if引導(dǎo)的虛擬條件從句中含有had, were, should等時，如將if省略，則要將had, were, should等移到主語前，構(gòu)成倒裝句：
Had you come yesterday, you would have seen him.
若你昨天來，你就會見到他了。
Should you require anything give me a ring.
如果需要什么，可以給我打電話。
Were it not for your help, I would still be homeless.
要不是你幫助，我會仍然無家可歸。
注意：省略if后提前的had不一定是助動詞
Had I money, I would buy it. 假若我有錢，我就會買它。
全部倒裝
全部倒裝是只將句子中的謂語動詞全部置于主語之前。
1) here, there, now,then, thus等副詞置于句首, 謂語動詞常用be,come, go, lie, run等表示來去或狀態(tài)的動詞。
例如：
Then came the chairman. 那時總裁來了。
Here is your letter. 你的信。
2)表示運(yùn)動方向的副詞或地點(diǎn)狀語置于句首，以out, in, up, down, off, away等副詞開頭，謂語動詞是表示“移動”的go, come, leave等句子里。
例如：
Ahead sat an old woman. 前面坐著一個老嫗。
Down went the small boat. 小船沉下去了。
注意:在完全倒裝的結(jié)構(gòu)里,如果主語是人稱代詞,則用正常語序。
3)表示地點(diǎn)的介詞詞組位于句首，謂語動詞是表示“存在”之意的be, lie, stand, exist等句子中。
South of the lake lies a big supermarket.
湖泊的南邊是一個大超市。
20 miles east of our school lies a modern swimming pool.
我們學(xué)校向東20英里有一個現(xiàn)代化的游泳池。
4) 在there be或者there live(stand, appear, seem, remain, exist….) 句型中。
部分倒裝
1.句首為否定或半否定的副詞或連詞。
如no, not,never, seldom, little, hardly, scarcely, rarely, at no time決不, by no means, on no account, inno case, many a time, under no circumstances, in no way, many a time, not until… 等。
例如：
He cares little about his clothes.
= Little does he care about his clothes.
他不在乎穿著。
I have never seen him before.
= Never have I seen him before.
= Never before have I seen him.
我以前沒見過他。
The mother didn't leave the room until the child fell asleep.
= Not until the child fell asleep did the mother leave the room.
孩子睡著了，媽媽才離開房間。
(Not until引出的主從復(fù)合句中，主句倒裝，從句不倒裝。即：后倒前不倒。注意：如否定詞不在句首不倒裝。)
例如：
Churchill was not only a statesman, but a poet.
= Not only was Churchill a statesman, but a poet.
丘吉爾不僅是個政治家，而且還是個詩人。
I shall by no means give up.
= By no means shall I give up. 我決不放棄。
必背：表示“剛……就……的倒裝結(jié)構(gòu)
Hardly had he started to leave when it began to rain.
他剛要離開，天就下起了雨。
Scarcely had he sat down when his mobilephone rang.
他剛坐下，手機(jī)就響了。
No sooner had he handed in his paper than he realized his mistakes.
他剛交卷就意識到出錯了。
Seldom is my son late for school.我兒子上學(xué)幾乎不遲到。
In no case should you touch it.無論如何你都不能碰它。
2.以否定連詞開頭作部分倒裝
如 Not only…but also, Hardly/Scarcely…when, No sooner… than等，前倒后不倒。例如：
Not only did he refuse the gift, he also severely criticized the sender. 他沒有收下禮物，還狠狠批評了送禮的人。
Hardly had she gone out when a student came to visit her. 她剛出門，就有個學(xué)生來訪。
No sooner had she gone out than a student came to visit her. 她剛出門，就有個學(xué)生來訪。
3. so, neither, nor作部分倒裝
表示另一主語“也…樣”時，用“So +be(have,助動詞或情態(tài)動詞)+主語”結(jié)構(gòu);而表示另一主語“也不…樣”時，用“NorNeither + be(have,助動詞或情態(tài)動詞)+主語”結(jié)構(gòu)。
例如：
Tom can speak French. So can Jack. 湯姆會講法語，杰克也會。
If you won't go, neither will I. 你不去，我也不去。
She won’t go. Neither/Nor will I.
她不走，我也不。
注意：如果前面所說的內(nèi)容既有肯定又有否定，或前后的謂語動詞形式不一致時，用“It is the same with +主語”結(jié)構(gòu)或用“So it is with +主語”結(jié)構(gòu)。
4.only+狀語在句首倒裝的情況。
only+副詞;或介詞短語;或狀語從句時，主句倒裝。
例如：
Only then did I see life was not easy.只有那時我才知道生活是不易的。
Only in this way, can you learn English well. 只有這樣，你才能學(xué)好英語。(only+介詞短語)
Only after being asked three times did he come to the meeting. 叫了三次，他才來參加會議。
Only yesterday did he find out that his watch was missing.(only+副詞)
Only when it began to rain did he finish his job.(only+狀語從句)
注：如果句子為主從復(fù)合句，則主句倒裝，從句不倒裝。
例如：
Only when he is seriously ill does he ever stay in bed. 病得狠重時，他才臥床休息。
5. so… that，such…that引導(dǎo)的結(jié)果狀語從句中，部分倒裝。當(dāng)so位于句首時，用”so +adj. + 主語+謂語”。
例如：
So frightened was he that he did not dare to move an inch. 他害怕得很，動也不敢動。
So difficult was the exam that most of the students failed to pass it. 考試如此難，以至于大多數(shù)同學(xué)沒能考過。
So stingy is she that none of us likes her.她太小氣，沒人喜歡她。
6. so作“也”講時，引導(dǎo)的句子用倒裝語序，表示前面所說的肯定情況也適用于另一人(或物)。其句型是：So + be(have，助動詞或情態(tài)動詞)+主語
She has been to Tokyo. So have I.
她去過東京，我也去過。
He can send emails to his former classmates. So can she.
他能電子郵件給以前的同學(xué)，她也能。
7. as, though引導(dǎo)的部分倒裝
as / though引導(dǎo)的讓步從句由于語法需要，可將表語或狀語提前(形容詞, 副詞, 分詞, 實(shí)義動詞提前)。
但需注意：
1)句首名詞不能帶任何冠詞。
2)句首是實(shí)義動詞, 其他助動詞放在主語后。如果實(shí)義動詞有賓語和狀語，隨實(shí)義動詞一起放在主語之前。
例如：
Shortest as/though she is, she is not the richest.(倒裝后，最高級前不用冠詞)
Child as he is, he knows a lot.(倒裝后，單數(shù)名詞前不用a)
Fail as I did, I would try again.(倒裝后，實(shí)義動詞提前，在主語后添加助動詞。)
注意：讓步狀語從句中，有though，although時，后面的主句不能有but，但是 though 和yet可連用。
當(dāng)as作“雖然”解，引導(dǎo)讓步狀語從句時，必須將表語、狀語或動詞原形提到as前面。
句子的倒裝語序有以下三種形式：
(1). 形容詞或副詞+as+主語+連系動詞be或?qū)嵙x動詞。
例如：
Rich as he is, he never spends a cent on clothes.
雖然他很富有，但他從不花一分錢在衣服上。
Much as I admire his courage, I don’t think he acted wisely.
我雖然佩服他的勇氣，但我認(rèn)為他這樣做是不聰明的。
(2). 名詞+as+主語+連系動詞be (注意句首的名詞不帶冠詞)。
例如：
Child as he is, he knows a lot.
盡管他是個孩子，但懂很多事情。
Boy as he was, he was chosen king.
盡管他還是個孩子，但卻被立為國王。
(3). 實(shí)義動詞+as+主語+助動詞[如果沒有助動詞，則要加上一個do(does或did)]。
例如：
Try as he may, he never succeeds.
盡管他很努力，但總是不成功。
Change your mind as you will, you will gain no additional support.
即使你改變主意，你也不會得到另外的支持。
8.一些表示頻率的副詞(如many a time, often等)位于句首時。
I have seen her taking a walk alone many a time.
Many a time have I seen her taking a walk alone.
我多次看到她獨(dú)自一人在散步。
She often came to my house in the past.
Often did she come to my house in the past.
過去她常到我家來。
高中英語的語法知識2
英語修飾詞，強(qiáng)調(diào)詞
什么是修飾語?
和限定詞一樣，修飾語修飾句子的意思。它們根據(jù)說話者的意圖改變其意思。修飾語是幫助你描述意思的最廣泛的一類詞。因此，它們可以是所有類型的詞類，如形容詞、形容詞從句、副詞、副詞從句、絕對短語、不定式短語、分詞短語和介詞短語。如果使用得當(dāng)，修飾語可以使任何句子更吸引人，更詳細(xì)，更有趣的讀者。修飾語給讀者更多的信息，創(chuàng)造一個更完整的情況。
例：
Amy gathered ingredients.
艾米收集原料。
例：
Young Amy, who just wanted to eat her favorite dessert to reward herself, enthusiastically gathered ingredients for a cake from the kitchen pantry, sneaking bits of sugar and chocolate as she left a trail of flour on the kitchen table and floor, a situation requiring her mother to spend so much time cleaning up that she couldn’t help Amy bake the cake.
年輕的艾米只想吃她最喜歡的甜點(diǎn)來獎勵自己，她從廚房的餐具室里熱情地收集蛋糕的配料，偷偷地在廚房的桌子和地板上留下一小片面粉，同時還偷了一些糖和巧克力，這種情況要求她母親花太多時間打掃衛(wèi)生，以致于她無法幫助艾米烤蛋糕。
上面這句話雖然很長，但比第一句講的故事要多得多。它也更有趣的閱讀，使你可能想知道更多的情況。
艾米為什么要獎勵自己?為什么她媽媽不幫她收集配料?該句子還包含以下每種類型的修飾語中的至少一種，如下所述。
形容詞(形容名詞或代詞)：young
年輕
形容詞從句(用作形容詞的描述性短語)：
who just wanted to eat her favorite dessert
只想吃她最喜歡的甜點(diǎn)的人
不定式短語(以不定式開頭或后跟動詞的描述性短語)：
to reward herself
獎勵自己
副詞(形容形容詞或動詞)：
enthusiastically
熱情地
介詞短語(以介詞開頭的描述性短語，青蛙可以對原木做的事情，如sit on, in, 或 on top of it)：
from the kitchen pantry
來自廚房的餐具室
分詞短語(以形容詞形式的動詞開頭的描述性短語，通常以-ing或-ed結(jié)尾)：
Sneaking bits of sugar and chocolate
偷一點(diǎn)糖和巧克力
狀語從句(一種做副詞的描繪性短語)：
She left a trail of flour on the kitchen table and floor.
她在廚房的桌子和地板上留下面粉痕跡。
絕對短語(附在句子上的不帶連詞的描述性短語，經(jīng)常修改整句話的意思)：
Her mother to spend so much time cleaning up that she couldn’t help Amy bake the cake.
母親花大量時間清理，她無法幫助艾米烤蛋糕。
從上面的每個修飾語可以看出，它們可以放在句子的任何部分來修飾任何類型的單詞或短語。
形容詞和副詞總是出現(xiàn)在它們所修飾的詞或短語的前面，但除此之外，大多數(shù)修飾語都可以放在它們聽起來最好的地方，它們將要修飾的東西最清楚的地方。
什么是限定詞?
限定詞是修飾語的一個子組，可以是副詞，可以是單詞或短語，通過限制動詞來改變動詞的意義。
不要說 Pam was working，這意味著Pam正在工作，你可以通過說 Pam was hardly working，來限制你描述的工作量。第二句幾乎沒有限定詞，它的意思與第一句完全不同。在這種情況下，Pam做的工作比以前少得多。
限定詞的一般用途是表示懷疑，或者限定你所說的話。你可以限制你所改變的動詞和形容詞的意義，如果你還沒有足夠的詞匯量，這將非常有用。把這些限定詞放在你想描述的動詞或形容詞前面。
下面列出了一些非常常見的限定符：
減輕某事的影響：
May/Might/Maybe/May be/Might/Could/Kind of/Sort of/Somewhat/Slightly
可能/也許/也許是/有點(diǎn)/稍微有點(diǎn)
例：
I might be going to Italy in June with my cousins, but I’m not sure yet.
我可能六月份和我的表兄弟們?nèi)ヒ獯罄?，但我還不確定。
The rain could fall, but the sun is out to it is hard to predict.
雨可能會下，但太陽出來了，很難預(yù)測。
Katie kind of wants to go to Disneyland, but she is afraid to ask her parents to take her.
凱蒂有點(diǎn)想去迪斯尼樂園，但她不敢讓父母帶她去。
一個較小的數(shù)字
Few/Not many/A small number/A minority/Some
少/不多/少數(shù)/少數(shù)
例：
A minority of voters approve of the new legislation that is being considered.
少數(shù)選民贊成正在考慮的新立法。
Few students enjoy learning from reading books, as they would prefer to try different things and learn by experimentation.
很少有學(xué)生喜歡從讀書中學(xué)習(xí)，因?yàn)樗麄兏矚g嘗試不同的東西，通過實(shí)驗(yàn)來學(xué)習(xí)。
I would like some peas, please.
請給我一些豌豆。
某事不會比它發(fā)生得更頻繁，或者比你期望的要少
Hardly/Hardly ever/Rarely/Infrequently/Seldom/Sporadically/Scarcely/For a short time
很少/偶爾/幾乎沒有/短時間內(nèi)
例：
This is scarcely the time to be doubting our plans, Harry.
哈利，現(xiàn)在幾乎不是懷疑我們計(jì)劃的時候。
It hardly ever rains here, so if you draw lines in the sand, you can come back and see them years later.
這里幾乎從不下雨，所以如果你在沙地上畫線，你可以在幾年后回來看。
The ice cream truck rarely comes by our neighborhood, but is very popular when it does.
冰淇淋車很少經(jīng)過我們附近，但很受歡迎。
To create doubt
表示懷疑
Unlikely/Improbable/Doubtful/Possibly/Probably/Not likely/Undecidedly/Apparently
不可能/可疑/可能/不可能/不確定/明顯不可能/不可能/也許/不可能/不確定/明顯
例：
To answer your question, it is highly unlikely that Cassie will be picked for the position.
回答你的問題，凱西被選上這個職位的可能性很小。
Don’t get your hopes up because your design is not likely to be selected.
不要因?yàn)槟愕脑O(shè)計(jì)不太可能被選中而抱有希望。
The doctor will probably have some time to see you in the afternoon, so come when you are available.
下午醫(yī)生可能有時間來看你，有空的時候來。
To make generalizations, or talk about multiple things that are related, but not the same
概括，或談?wù)摱喾N相關(guān)但不相同的事情
Basically/Essentially/Generally/Pretty/Rather/Virtually
基本上/大體上/一般地/漂亮/相當(dāng)于/實(shí)際上
例：
“Traveling in the different countries in Asia is basically the same,” said John, who had never been to any of the countries in Asia.
從未去過亞洲任何一個國家的約翰說：“在亞洲的不同國家旅行基本上是一樣的?！?/p>
Essentially, the point of the festival is to celebrate the great things that have happened in the past year.
從本質(zhì)上講，節(jié)日的意義在于慶祝過去一年發(fā)生的大事。
Virtually every tournament only lets boys compete, probably because everyone is afraid to be beaten by a girl.
幾乎每場比賽都只讓男孩參加，可能是因?yàn)槊總€人都害怕被女孩打敗。
限定詞不限于以上列表，可以是長短語，也可以是單個單詞。
什么是強(qiáng)調(diào)詞?
強(qiáng)調(diào)詞是另一類特殊的修飾語。它們具有與限定詞相反的效果，并加強(qiáng)(而不是削弱)它們修改的單詞和短語的含義。
They are either positive (like very) or negative (like definitely not).
它們要么是積極的(像非常)要么是消極的(像絕對不是)。這兩類強(qiáng)調(diào)詞的例子如下：
肯定強(qiáng)調(diào)詞
Very/Extremely/Absolutely/Completely/Greatly/Too/So/Totally/Utterly/Highly/Rather/Really/Exceptionally/Particularly/Seriously/Quite (in American, but not British, English)/Awfully (be careful: awful means very bad, but awfully usually describes some great, like The cake was awfully delicious!)
非常的/絕對的/完全的/非常的/太多的/所以的/完全的/程度高的/相當(dāng)?shù)?非常的/特別的/認(rèn)真的/相當(dāng)?shù)?在美國，但不是英國，英語)/Awfully(小心：awful 的意思是非常糟糕，但是awfully通常描述一些偉大的，如 The cake was awfully delicious! 蛋糕是非常美味的!)
例：
The boss was very adamant that the software be changed this way, so we had better listen to his demands.
老板非常堅(jiān)決地要求這樣修改軟件，所以我們最好聽聽他的要求。
I completely agree with Nathan, even though we never agree on anything.
我完全同意內(nèi)森的觀點(diǎn)，盡管我們從來沒有達(dá)成一致。
Sally really wanted to kiss Liam that night.
那天晚上莎莉真的很想吻利亞姆。
否定強(qiáng)調(diào)詞
Never/At all/What on earth…?
從來沒有/根本沒有/到底是什么…?
e. What on earth is Mindy doing? To question Mindy’s actions.
明迪到底在干什么?質(zhì)疑明迪的行為。
Why… ever…?
究竟為什么?
e. Why did I ever agree to help you move your furniture? To indicate regret or a problem.
我究竟為什么同意幫你搬家具?表示遺憾或問題。
Dangerously/Seriously/Ever again/Bitterly (goes with specific words, only, including cold, unhappy, disappointed, sad, )
危險(xiǎn)的/嚴(yán)肅的/永遠(yuǎn)的/痛苦的(僅限于特定的詞語，包括冷漠、不快樂、失望、悲傷)
例：
Luke never wants to see Philip ever again.
盧克再也不想見菲利普了。
My son does not want to attend this college at all!
我兒子根本不想上這所大學(xué)!
You are getting dangerously close to the edge of my patience.
你正危險(xiǎn)地接近我的忍耐極限。
一個更大的數(shù)字
Many/Most/Some/Lots of/Numerous/Countless/A majority/Mostly/Various
很多/大多數(shù)/一些/大多數(shù)/數(shù)不盡的/大多數(shù)的/各種各樣的
例：
Countless efforts have been made to change the system, but nothing has worked.
為改變這一制度已經(jīng)做了無數(shù)的努力，但什么也沒有奏效。
A majority of the benches in this park were donated by people from this neighborhood.
公園里的長椅大部分是由附近的人捐贈的。
Herbert was mostly just curious why you designed your office this way.
赫伯特只是好奇你為什么要這樣設(shè)計(jì)你的辦公室。
某事經(jīng)常發(fā)生，或比你期望的更普遍
Often/Frequently/Commonly/For a long time/Usually/Sometimes/Repeatedly
經(jīng)常/頻繁地/通常地/長時間/常/有時/反復(fù)
例：
For a long time, I thought that all rabbits just ate carrots all the time.
很長一段時間以來，我一直以為所有的兔子都只吃胡蘿卜。
She frequently stops by our shop to buy a jar of pickles.
她經(jīng)常來我們店里買一罐泡菜。
I have told you repeatedly not to bother me when I am working, have I not?
我反復(fù)告訴過你，我工作時不要打擾我，是嗎?
何時以及如何使用修飾詞、限定詞和強(qiáng)調(diào)詞?
在很大程度上，使用這些單詞和短語可以描繪出一幅更加豐富多彩和充滿活力的畫面，你想說什么。它們有助于提供更多的細(xì)節(jié)和顯示完整的圖片。
修飾語可以用在句子的任何地方，可以有多種不同的形式。限定詞和強(qiáng)調(diào)詞是經(jīng)常出現(xiàn)在它們所修飾的詞或短語前面的詞或短語。然而，使用太多會使你的寫作或演講變得雜亂無章。減少你使用的單詞數(shù)量和句子復(fù)雜程度的一個好方法就是復(fù)習(xí)你的寫作。
例：
Very important = crucial, central, essential
非常重要=關(guān)鍵、中心、關(guān)鍵
Very unimportant = trivial, irrelevant
非常不重要=微不足道，無關(guān)緊要
Very cold = chilly or freezing
非常冷=寒冷的，冷嗖嗖的
Very hot = sweltering
非常熱=悶熱的
Very confusing = puzzling, perplexing
非常困惑的=令人疑惑的
Very slow = sluggish
非常慢=慢悠悠的
Very fast = speedy, rapid, swift
非常快=迅速的
Very large = enormous, giant, huge
非常大=巨大的
Very small = nonexistent, tiny
非常小=不存在的，極小的
高中英語的語法知識3
虛擬語氣用法歸納
虛擬語氣用法歸納
虛擬語氣對于很多高中生而言都是一個困擾。難點(diǎn)有兩個
一. 何時用?
二. 何種形式?
一、何時用?
英語中的語氣分為陳述語氣、祈使語氣、虛擬語氣等。虛擬語氣表示說話者做出的假設(shè)并非事實(shí)，或難以實(shí)現(xiàn)的，甚至表達(dá)相反的概念，或者表示主觀愿望或某種強(qiáng)烈的感情。虛擬語氣通過謂語動詞的特殊形式來表示。
二、何種形式?
為方便同學(xué)們記憶，不妨簡單歸納如下：
1.退后時態(tài)型
2. 情態(tài)動詞+have done
3.should型。
1. 退后時態(tài)型
即依據(jù)所想表達(dá)的時間，現(xiàn)在的虛擬退后為過去時，過去的虛擬退后為過去的過去，即過去完成時，將來的虛擬退后為過去將來時(有些從句不用將來時，單獨(dú)考慮)。
退后時態(tài)型包括：
1. if條件句 2. as if/ as though 3.even if/ even though 4. if only 5. wish 6. would rather. 以上六種從句中。
1.if虛擬條件句
如：
(1) 現(xiàn)在時的條件句中的虛擬語氣。eg：
If he were free now, he would help us.
要是他現(xiàn)在有空的話，它會幫助我們的。
(2) 過去時的條件句中的虛擬語氣。eg：
If I had got there earlier, I would have met Mr. Li.
如果我早點(diǎn)到那兒，我就會見到了李先生。
(3) 將來時的條件句中的虛擬語氣。eg
If he were to come/ should come/ came here tomorrow, he would tell us about it.
明天萬一他要來的話，他會通知我們一聲。
運(yùn)用條件句中的虛擬語氣時，須注意的幾個問題:
(1) 注意：if條件句中因?yàn)橹鲗默F(xiàn)，不用將來時，所以與現(xiàn)在時間虛擬形式一致，無非增加兩種形式should do 、 were to do，整體看依然符合上述“現(xiàn)在的虛擬退后為過去時，過去的虛擬退后為過去的過去，即過去完成時，將來的虛擬退后為過去將來”。
(2)錯綜時間虛擬條件句，即主、從句的動作不是同時發(fā)生時，依據(jù)表格主從句動詞形式區(qū)別對待。
①從句的動作與過去事實(shí)相反，而主句的動作與現(xiàn)在或現(xiàn)在正在發(fā)生的事實(shí)不符。eg：
If I had worked hard at school, I would be an engineer now, too. 如果我在學(xué)校學(xué)習(xí)刻苦的話，我現(xiàn)在也會是工程師了
②從句的動作與現(xiàn)在事實(shí)相反，而主句的動作與過去事實(shí)不符。如：
If he were free today, we would have sent him to Beijing.
如果他今天有空的話， 我們會已經(jīng)派他去北京了。
(3)含蓄條件句
without,but for, or, otherwise等詞可以表達(dá)假設(shè)，相當(dāng)于if條件句。主句動詞形式依據(jù)時間確定
eg：
Without electricity, our life would be greatly different.
But for your help last term, I would have failed the exam.
We didn't know his telephone number; otherwise we would have telephoned him.
我們不知道他的電話號碼，否則我們就會給他打電話。
(4)當(dāng)虛擬條件句的謂語動詞含有 had, should, were時, if 省略，將 had, should, were置于句首。為方便記憶，按諧音可記為：一馬當(dāng)先還(had)數(shù)(should)我(were)，一馬當(dāng)即為將 were, should, had等詞置于句首?！咀ⅰ咳魲l件從句為否定句，否定詞not不提前。
eg：
(1)Were he free now, he would help us.
要是他現(xiàn)在有空的話，它會幫助我們的。
(2)Had I got there earlier, I would have met Mr. Li.
如果我早點(diǎn)到那兒，就會見到了李先生。
(3)Were he to come here tomorrow, he would tell us about it.
Should he come here tomorrow, he would tell us about it.
明天萬一他要來的話，他會通知我們一聲。
(4)Had I not got there late, I would have met Mr. Li.
如果我早點(diǎn)到那兒，就會見到了李先生。
2.動詞wish后接賓語從句時，從句謂語要用虛擬語氣。
表示與現(xiàn)在事實(shí)相反的愿望，從句謂語用一般過去時或過去進(jìn)行時(同樣be動詞換成were);表示與過去事實(shí)相反的愿望，從句謂語用過去完成時had done;
表示將來沒有把握或不太可能實(shí)現(xiàn)的愿望，用過去將來時would /could+動詞原形。
注意如果將wish改為過去式wished， 其后that 從句中的動詞形式不變。如：
1) How I wish / If only I could be of some use.
我希望我能有什么用處。
2) How I wish / If only I had met him yesterday!
注意： 表示與過去事實(shí)相反的愿望，從句謂語除用過去完成時had done外，也可以用would / could+have +過去分詞(注意這里的情態(tài)動詞不能用should)
I wish I could have studied hard at university.
3. would rather之后的賓語從句常表示與客觀事實(shí)不相符的一種愿望，其虛擬語氣的形式為：
過去虛擬 用had + done
現(xiàn)在或者將來虛擬 用過去時(be用were )
eg：
1)I’d rather you had seen the film yesterday.
我倒想你昨天看過了這場電影。
2)I’d rather you were here now.
我倒想你現(xiàn)在在這兒。
3)We’d rather you went there tomorrow.
我們倒想你明天去那兒。
4. 其他
1)When a chopstick is partly in water, it looks as if it were broken.
2)Even if he were here, there would be nothing to be done.
2. 情態(tài)動詞+have done
should/ ought to/ could/ might/ needn’t/ would/ would like to/ would love to/ would rather 等情態(tài)動詞后面+have done，表達(dá)對過去的虛擬，譯為過去本應(yīng)該，過去本能夠，過去本不必等。
eg：
1) I would/ would like to have attended the concert, but an unexpected visitor came then.
2) It was Sunday yesterday; he needn’t have gone to work. (本不必去卻去了)
3. should 型
1. 表達(dá)“建命要堅(jiān)”等意義的詞后面的名詞從句中，從句謂語由“should+動詞原形”構(gòu)成，其中的should可以省略。
建議：suggest/advise/propose/recommend/urge
命令：order/command
要求：demand/require/request
堅(jiān)持：insist
eg：
1)The doctor advised that he change his job.
醫(yī)生勸他換工作。(賓語從句)
2)The workers on strike demanded that this tax be abolished.
罷工的工人們要求取消這種稅。(賓語從句)
3)The committee proposed (that) Mr. Day be elected.
委員會建議推選戴先生。(賓語從句)
4)He took no notice of the doctor’s suggestion that he (should) not smoke.
他對醫(yī)生對他不要抽煙的建議置之不理。(同位語從句)
5)My proposal is that the matter be put to the vote at once.
我提議對此問題立刻進(jìn)行表決。(表語從句)
6) It is required in the notice that everyone (should) wear formal suits
通知中要求所有人要著正裝。(主語從句)
7)They urged that relief work should be given priority.
他們敦促將救濟(jì)工作放在優(yōu)先位置。
注意：
1)suggest譯為“表明”、“暗示”時，不需要虛擬。
He suggested that we (should) stay for dinner.
他建議我們留下吃飯。
What he said suggested that he was a cheat.
他說的話表明他是個騙子。
2)動詞insist后接賓語從句時，除可用虛擬語氣外，也可用陳述語氣，兩者的區(qū)別是：若謂語動詞所表示的動作尚未發(fā)生，或尚未成為事實(shí)，則用虛擬語氣;若謂語動詞所表示的動作已經(jīng)發(fā)生，或已經(jīng)成為事實(shí)，則要用陳述語氣。比較：
He insisted that I had read his letter.
他堅(jiān)持說我看過他的信。
He insisted that I should read his letter.
他堅(jiān)持要我看他的信。
2. It is +表達(dá)情況緊迫性或者強(qiáng)烈情緒，觀點(diǎn)的n/adj/done +that +主語從句，從句的謂語動詞常用should+原形且should可以省略。
表示緊迫的或者表強(qiáng)烈情緒，觀點(diǎn)的詞如：advisable, critical, desirable, essential, imperative, important, necessary, urgent, vital, natural, strange, surprising, a pity, a miracle, desire, urge等。
eg:
1)Do you think it is necessary that he (should) not be sent to Miami.
2)It’s vital that you make a decision right now.
你立刻就做決定是至關(guān)重要的。
3)It is urged that relief work should be given priority.
他們敦促將救濟(jì)工作放在優(yōu)先位置。
4)It is strange that such a person should be our friend.(should表示“竟然”，不可省)
奇怪的是這樣一個人會成為我們的朋友。
3. 虛擬語氣句型It is 或was (high) time that +從句，從句的謂語動詞形式用一般過去時
或者should do形式且該should不可以省略。
eg: It is (high) time that we went /should go to school.
4. 在for fear that，in case，lest引導(dǎo)的從句中，虛擬語氣從句動詞形式為：(should) + do，并且should能省略(for fear that，lest)，in case后不能省略。
eg:
1)She examined the door again for fear that a thief (should) come in.
她又把門檢查了一遍，以防盜賊的進(jìn)入。
2) He started out earlier lest he (should) be late.
他早早地就出發(fā)了以防遲到。
注意：in case從句中可能性較大時，用陳述語氣
eg: You’d better take an umbrella in case it rains.
高中英語的語法知識總結(jié)相關(guān)文章：