一、概念:
介詞（是prepositions,簡稱prep),又稱前置詞,是英語中最活躍的詞類之一,連接主語和表語.特別是一些常用介詞的搭配力特別強(qiáng),可以用來表示各種不同的意思.英語里大部分習(xí)語都是由介詞和其他詞構(gòu)成的.介詞在句中一般不重讀.在定語從句“介詞+who/which”的結(jié)構(gòu)中,不能用that 代替who/which.She is a good student from who we should learn.
編輯本段二.相關(guān)知識點(diǎn)精講
介詞口訣：自從以當(dāng)為按照,由于對于為了到；和跟把比在關(guān)于,除了同對向往朝；用在名詞代詞前,修飾名代要記牢..
編輯本段1.表示地點(diǎn)位置的介詞
1)at ,in, on, to,for at (1)表示在小地方; (2)表示“在……附近,旁邊” in (1)表示 在大地方; (2)表示“在…范圍之內(nèi)”. on 表示毗鄰,接壤,“在……上面”. to 表示在……范圍外,不強(qiáng)調(diào)是否接壤；或“到……” 2)above, over, on 在……上 above 指在……上方,不強(qiáng)調(diào)是否垂直,與 below相對； over指垂直的上方,與under相對,但over與物體有一定的空間,不直接接觸. on表示某物體上面并與之接觸. The bird is flying above my head. There is a bridge over the river. He put his watch on the desk. 3)below, under 在……下面 under表示在…正下方 below表示在……下,不一定在正下方 There is a cat under the table. Please write your name below the line. 4)in front [frant]of, in the front of在……前面 in front of…意思是“在……前面”,指甲物在乙物之前,兩者互不包括；其反義詞是behind（在……的后面）. There are some flowers in front of the house.(房子前面有些花卉.) in the front of 意思是“在…..的前部”,即甲物在乙物的內(nèi)部.反義詞是at the back of…（在……范圍內(nèi)的后部）. There is a blackboard in the front of our classroom. 我們的教室前邊有一塊黑板. Our teacher stands in the front of the classroom. 我們的老師站在教室前.(老師在教室里) 5）beside,behind beside 表示在……旁邊 behind 表示在……后面
編輯本段2.表示時間的介詞
1)in , on,at 在……時 in表示較長時間,如世紀(jì)、朝代、時代、年、季節(jié)、月及一般（非特指）的早、中、晚等. 如 in the 20th century, in the 1950s, in 1989, in summer, in January, in the morning, in one’s life , in one’s thirties等. on表示具體某一天及其早、中、晚. 如on May 1st, on Monday, on New Year’s Day, on a cold night in January, on a fine morning, on Sunday afternoon等. at表示某一時刻或較短暫的時間,或泛指圣誕節(jié),復(fù)活節(jié)等. 如at 3:20, at this time of year, at the beginning of, at the end of …, at the age of …, at Christmas, at night, at noon, at this moment等. 注意：在last, next, this, that, some, every 等詞之前一律不用介詞.如：We meet every day. 2)in, after 在……之后 “in +段時間”表示將來的一段時間以后； “after+段時間”表示過去的一段時間以后； “after+將來的時間點(diǎn)”表示將來的某一時刻以后. 3)from, since 自從…… from僅說明什么時候開始,不說明某動作或情況持續(xù)多久； since表示某動作或情況持續(xù)至說話時刻,通常與完成時連用.since表示"自（某具體時間）以來",常用作完成時態(tài)謂語的時間狀語. since liberation（1980）自從解放（1980年）以來 They have been close friends since childhood． 他們從小就是好朋友. （1）since the war是指"自從戰(zhàn)爭結(jié)束以來",若指"自從戰(zhàn)爭開始以來",須說"since the beginning of the war". （2）不要將since與after混淆. 比較：He has worked here since 1965．（指一段時間,強(qiáng)調(diào)時間段）自從1965年以來,他一直在這兒工作. He began to work here after 1965． （指一點(diǎn)時間,強(qiáng)調(diào)時間點(diǎn)）從1965年以后,他開始在這兒工作. 4)after, behind 在……之后 after主要用于表示時間； behind主要用于表示位置. 時間名詞前介詞用法口訣 年前周前要用in 具體日子要用on 遇到幾號也用on 上午下午得是in 要說某日上下午 用on換in記清楚 午夜黃昏用at 黎明用它也不錯 at用在時分前 說“差”可要用上to 說"過''要用past
編輯本段3.表示運(yùn)動方向的介詞：
across, through 通過,穿過 across表示橫過,即從物體表面通過,與on有關(guān),為二維 through穿過,即從物體內(nèi)部穿過,與in有關(guān),為三維.
編輯本段4.表示“在……之間”的介詞：
表示“在……之間”的介詞在英語中屬于方位介詞,如in front of ,behind ,on, in, near, under, up between, among between指在兩個人或兩個事物之間； among指在三個或三個以上的人或事物之間.
編輯本段5.表示其他意義的介詞
1)on ,about 關(guān)于 on 表示這本書,這篇文章或演說是嚴(yán)肅的,或?qū)W術(shù)性的,可供專門研究這一問題的人閱讀； about表示內(nèi)容較為普通,不那么正式. 2)by, with, in 表示方法、手段、工具 by 以……方法、手段或泛指某種交通工具； with 表示用 …工具、手段,一般接具體的工具和手段； in 表示用…方式,用…語言(語調(diào)、筆墨、顏色)等； 3)except, besides 除了 except 除……之外,不包括在內(nèi)； besides 除……之外,包括在內(nèi). Except for Mr. Wang, we went to see the film.(王先生沒去) Besides Mr. Wang, we also went to see the film.(王先生也去了)
編輯本段其它常用介詞
介詞在英語詞匯中所占比例很小,但它們的用法卻非常靈活,復(fù)雜.下列為常用介詞及含義: 1）about 關(guān)于,附近,大約,周圍,隨身. I have bought a book about Shakespearean. 我買了一本有關(guān)莎士比亞的書. There are about fifteen trees in the picture. 大約有十五棵樹在圖片里. 2）above 在.上,高出,以上,超過,在...上游. The plane is flying above the clouds. 飛機(jī)在云上飛行. I think the man is above sixty years old. 我想那人有六十多歲了. 3）across 橫過,對面,交叉,在...的對面. Can you swim across the river? 你能游過河嗎? We live across the street. 我們住在街的對面. 4）after 在...后面,依照. He went home after school. 他放學(xué)后就回家了. Read after me, please. 請跟我朗讀. 5）against 撞到,靠著,反對,違背, The car hit against the tree. 汽車撞了樹. He is standing against the wall. 他靠墻站著. 6）along 沿著,順著. They are walking along the river. 他們沿著河行走. 7）among 在...當(dāng)中.（三者或三者以上） He is the tallest among them. 他是他們當(dāng)中個子最高的. 8）around 在...的周圍,在...那一邊. They sat around the table talking the news. 他們繞桌而坐談?wù)撔侣? There is a drugstore around the corner. 拐角處有一家藥店. 9）as 作為. He doesn't like people treat him as a child. 他不喜歡人們把他當(dāng)小孩子對待. 10）at 在...時刻,在...點(diǎn)鐘,在...歲時, 向,在...之中,按...速度,值(賣)...錢, 在...（強(qiáng)調(diào)地點(diǎn)） He always gets up at six in the morning. 他時常早上六點(diǎn)鐘起床. He shot at the bird but missed it. 他向鳥射擊,但是沒射中. The car goes at eighty miles an hour. 汽車以每小時八十公里的速度行駛. 11）before 在...的前面(位置),在...之前(時間) He took a picture before the car. 他在汽車前照了張照片. He can't finish his work before supper. 晚飯前他完不成工作. 12）behind 在...的后面(位置), 落后于,不如, 遲于,晚于(時間) Are there any brooms behind the door. 門后有掃帚嗎? All of us are behind him in mathematics. 我們數(shù)學(xué)都不如他. 13）below 在...之下,低于, There are four lights below the ceiling. 天花板下面有四盞燈. The murderer run away below the police's eyes. 殺人犯從警察眼皮底下跑了. 14）beside 在...的旁邊,在...之外,與...相比. He found the body beside the river. 他在河邊發(fā)現(xiàn)了尸體. Beside yours, my computer is too slow. 與你的計(jì)算機(jī)速度相比,我的就慢多了. 15）besides 除...之外, 還有... We are all here besides Bowe. 除鮑外,我們也都來了. 16）between 在...兩者之間, The relations between the two countries has improved since then. 兩國的關(guān)系從那以后得到了改善. 17）beyond 在...那邊, The shop you are looking for is beyond the street, you can't miss it. 你要找的商店在街的那邊,你不會找不到的. 18）but 除去. He has nothing but money. 他除錢以外什么都沒有. 19）by 被..., 在...的近旁 , 在...之前, 不遲于, 以...為手段. The classroom was cleaned by the students. 教室由學(xué)生們打掃干凈了. Miss Lucy came to China by air. 露西小姐是乘飛機(jī)來中國的. 20）down 沿著...望下. She walked down the street. 她沿著街道走. 21）during 在...期間,在...時候. During the holiday, we went to the south. 我們假期去了南方. 22）except 除...之外. He knows nothing except English. 他除英語以外什么都不知道. 23）for 為..., 因?yàn)?.., 至于... . He works for this company. 他為這家公司工作. She came back to the classroom for she had left her books in the classroom. 她返回到教室是因?yàn)榘褧粼诹四抢? 24）from 從..., 來自..., 因?yàn)? Where are you from? 你是哪里人? He died from an accident. 他死于一場事故. 25）in 在..., 在...之內(nèi),從事于..., 按照..., 穿著. He was born in 1992. 他生于1992年.
連詞就是起連接作用的詞,and,補(bǔ)充當(dāng)任何成分.
（一）,連詞主要有but ,however,yet,although,on the contrary,while
,and, then, first second,or,not only...but also...,both...and...,neither...nor...
（二）,并列連詞和從屬連詞按語義分如下幾種：
A,常見的表示語義引申的并列連詞有：1.and
Justice is on your side. And justice will triumph over injustice. 正義在你們一邊,而正義是會戰(zhàn)勝非正義的.
2. neither... nor
She could neither speak the language nor write it. 這種語言她既不會說,也不會寫.
3. both... and
A man should have both courage and perseverance.一個人既要有勇氣又要有毅力.
4. not only... but also
We should not only be bold, but also be cautious. 我們不僅要大膽,而且要謹(jǐn)慎.
5. as well as
I have read one of his novels as well as a few of his plays. 我讀過他的一本小說和幾個劇本.
B,表示選擇的并列連詞有：
1. or
You may do it yourself, or ask someone else to do it. 你可以自己做或者讓別人做.
2. either... or
I left it either on the table or in the drawer. 我不是把它放在桌子上了,就是放在抽屜里了.
除了表示選擇外,or和either... or還可以表示否定的條件：
1) Now I must go or (if not) I shall be late for the party. 我現(xiàn)在得走了,否則晚會我就要遲到了.
2) You'll either behave yourself, or you'll never go out with me. 你要么老實(shí)點(diǎn),要么就永遠(yuǎn)不能跟我一起出去.
C,表示轉(zhuǎn)折或?qū)Ρ鹊牟⒘羞B詞有：
1. but
He tried hard but he was unsuccessful. 他做了很大努力但沒有成功.
2. yet
The car was old, yet it was in excellent condition. 這輛車子很舊,但仍處于良好的狀態(tài).
3. however
She felt ill. She went to work, however, and tried to concentrate. 她病了.然而她照舊去上班,并且盡力集中精神工作.
4. nevertheless
I don't know anything against that man; nevertheless I don't trust him. 我對那個人沒有什么不良的看法,但我不能信賴他.

D,表示因果關(guān)系的并列連詞有：
1. for
You'd better put on your sweater, for it's rather cold outside. 你最好把毛衣穿上,外邊相當(dāng)冷.
2. so
My sister is expecting me,so I must be off now. 姐姐在等我,因此我得走了.
3. therefore
You are right, therefore we should support you. 你是對的,所以我們應(yīng)當(dāng)支持你.
4. hence
I fell off my bike yesterday—hence the bruises. 我昨天騎自行車摔倒了——所以青一塊、紫一塊的.

從屬連詞是用來引導(dǎo)從句的.分為如下幾種：
A,引導(dǎo)時間狀語從句的從屬連詞有：
1. when
There was prolonged applause when he began to speak. 他開始講話時響起了經(jīng)久不息的掌聲.
2. while
We should strike while the iron is hot. 我們要趁熱打鐵.
3. as
As (When) he entered, the hall burst into thunderous applause. 當(dāng)他進(jìn)來時,全場發(fā)出雷鳴般的掌聲.
4. after
After I visit Shanghai I'll travel up the Yangtze. 訪問上海之后,我將溯長江而上.
5. before
It would be months before he was fit for the work. 要過好幾個月他才能適應(yīng)工作.
6. since
It is just a week since we arrived here. 我們到這里才一個星期.
7. until (till)
I shall stay here until (till) I've completed my studies. 我要在這里待到學(xué)習(xí)結(jié)束為止.
8. as soon as
As soon as he got well, he went back to work. 他病一好就回去上班了.
9. once
Once he said that, I knew he was lying. 他一說這話我就知道他在撒謊.
B,引導(dǎo)原因狀語從句的從屬連詞有：
1. because
He failed because he was too careless. 因?yàn)樗中?所以失敗了.
2. as
As it was already rather dark, we decided to stop at the temple for the night. 因?yàn)橐呀?jīng)相當(dāng)晚了,我們決定在廟里待一夜.
3. since
Since you don't want to go, we won't force you to. 既然你不愿意去,我們也不勉強(qiáng)你.
4. now that
Now that you are all back, we'd better start the work right away. 你們既然都回來了,我們最好馬上就開始工作.
5. considering (that)
They did the job quite well considering (that) they had no experience. 考慮到他們沒有什么經(jīng)驗(yàn),這項(xiàng)工作他們已經(jīng)干得不錯了.
6. seeing that
Seeing that (Since) nobody was very enthusiastic about it, they decided to cancel the trip. 由于都沒有很高的熱情,他們決定取消這次旅行.
C,引導(dǎo)條件狀語從句的從屬連詞有：
1. if
If you can do it, so can I. 你要是能辦到,我也能辦到.
2. even if
We wouldn't lose heart even if we should fail ten times. 我們就是失敗十次也不灰心.
3. unless
I won't go unless you want me to. 除非你要我去,否則我是不會去的.
4. in case
We'd better take our raincoats in case it should rain (rains). 我們最好把雨衣帶著以防下雨.
5. provided /providing (that)
I'll come provided (providing) (that) you let me know in good time. 你要是及時通知我是會來的.
6. suppose/supposing (that)
Suppose (Supposing) (that) he won't agree, what shall we do? 假如他不同意,我們怎么辦?
7. as (so) long as
You may use the room as long as you keep it clean. 只要保持清潔你可以用這個房間.
8. on condition (that)
I'll lend you the book on condition (that) you return it on Monday. 只要你能在星期一還我,這本書我就借給你.
D,引導(dǎo)讓步狀語從句的從屬連詞有：
1. although / though
Everybody worked with great enthusiasm although/though the weather was extremely cold. 雖然天氣很冷,大家工作得非常起勁.
2. even if (though)
Even if I have to walk all the way I'll get there. 即使我得一路走著去,我也要去那里.
E,引導(dǎo)比較狀語從句的從屬連詞有：
1. than
We have produced 20% more cotton this year than we did last year. 我們今年棉花產(chǎn)量比去年高百分之二十.
2. as (so)...as
He doesn't play half as well as his sister. 他演奏的水平不及他姐姐的一半.
F,引導(dǎo)目的狀語從句的從屬連詞有：
1. lest
She explained again and again lest people should misunderstand her. 她一再解釋唯恐人們誤解.
2. so that
Speak clearly so that we may understand you. 講話要清楚,以便我們能聽明白.
3. in order that
He assigned us some books to read at home in order that (so that) we might have a deeper understanding of the subject. 他指定幾本書給我們回家看,以便我們對這一主題有一個較深的了解.
G,引導(dǎo)結(jié)果狀語從句的從屬連詞有：
1. so...that
She was so moved that tears came to her eyes. 她感動得熱淚盈眶.
2. such...that
It was such a boring speech that I fell asleep. 演講枯燥乏味,聽得我都睡著了.
另外:引導(dǎo)名詞性從句的連詞有三個：(1)that (本身無意義),(2)whether (or not),(3)if.例如：
That they will refuse the offer is unlikely. 他們不太可能會拒絕這個建議.
I don't know whether (=if) these figures are accurate. 我不知道這些數(shù)字是否精確.
需要注意的是：whether (or not) 可引導(dǎo)大部分名詞性從句；if僅可引導(dǎo)賓語從句,而且不可跟or not.例如：
Whether (≠if) they will come or not won't make much difference. 他們來不來關(guān)系不大.
I wonder if (=whether) she has received our telegram. 我不知道她是否收到了我們的電報.