before的用法歸納

1、before 的用法是很多的人都比較想要了解的，在眾人的心中before 的用法是比較難的，我們都非常想要去了解before 的用法，但是又談何容易呢?為了讓大家更加快速的了解 before 的用法，下面我們就和教師一起去看看吧，希望對大家有所幫助。prep.在之前 ;先于，優(yōu)于 ;當(dāng)著 的面 ;與其 conj.在之前 ;在以前 ;比早些 ;與其 adv.先前，從前 ;在前，在前方before 一詞含義廣泛，是高考考查的熱點詞匯之一，但部分考生對該詞的用法模糊不清。為了幫助大家掌握，現(xiàn)就對 before 的用法歸納如下：一、 before 用作連詞1. before 用作連詞時，意思是 “在之

2、前 ;還沒來得及 就”。 強調(diào)主句或從句謂語動詞表示的動作發(fā)生得過早或過快 ?例如：Before she could move, she heard a great noise, which grew to a terribleroar. 她還沒來得及動彈， 就聽見有很響的聲音， 接著就成了可怕的隆隆轟鳴聲。Before I could say a word, she had stormed out of the room. 不等我說一句話，她就沖出了房間。Don t count your chickens before they are hatched不.要高興得過早。I must fini

3、sh my homework before I watch TV我.必須做完作業(yè)才能看電視。 It still took seven years before they finally got married. 過了七年他們才最終得以成婚。It will be only a few minutes before she comes back.她過幾分鐘就會回來。 He announced the ending of the meeting before I could get in a word. 沒容得我插上一句話 ,他就宣布散會了 ?Someone called me up in the

4、middle of the night, but they hung up before I could answer the phone.有人半夜給我打電話 ,但我還未來得及接他就把電話掛斷了 ?They had talked only a few minutes before they found they were quite different in opinion. 他們才談了幾分鐘就發(fā)現(xiàn)他們的意見很不一致 ?注意： before 從句若是一個將來的動作，則用一般現(xiàn)在時代替一般將來時，如上句中的 comes。2. 用于 It + be + 時間段 + before.句型中，意思是 “

5、在之后才 ”。例如：It will be five years before I come back.我五年后才能回來。It was not long before the enemy was driven out of their country.不久之后，敵人就被趕走了。如果主句中用否定式，則表示“不多久 就”。It won t be long before they understand each other.他們不久就會互相了解的。3. 還有 “趁(還沒有 ) ”之意。例如：They are thinking of buying the house before the prices

6、go up. 他們正在考慮趁房價未漲時把房子買下來。Do it before you forget it. 趁早動手，以免忘了。二、 before 用作介詞before 用作介詞時 , 可以指時間 “earlierthan 在之前 ”，也可以指位置“ in front of在之前 ”。例如：（1）表示時間，與after 相對。如：August comes before September. 8月份在 9 月份之前。There is nothing that has not been bitter before being ripe. 凡事在成熟前， 都是有苦味的。（2）表示順序，與after

7、相對。如：Ladies before gentlemen女.士優(yōu)先。（3）表示位置，與 behind 相對（相當(dāng)于 in front of ）。如：Before Lucy is Lily莉.莉在露茜的前面。Dont put the cart before the horse.不要本末倒置。（4）表示 “在面前；與 面對面 ”。如：The poor little boy was brought before the headmaster. 那個可憐的小男孩被帶到校長面前。He was brought before the judge. 他被帶到法官面前。（5）表示 “寧可 而不愿 ”。如：Dea

8、th before dishonour. 寧死不辱。三、 before 用作副詞（ 1）before 用作副詞時，意思是 “at an earlier time / in the past以前 ”。表示 “以前；已經(jīng) ”，單獨在句中作狀語，句子常用完成時態(tài)。如：I have seen that film before.我以前看過那部電影。I ve seen the film Titanic before我.以前看過泰坦尼克這部電影。I have never seen such beautiful flowers before. 我以前從未見過如此美麗的鮮花。注意：區(qū)別于 ago: ago 用在

9、時間段之后，表示某個時間點，句子用一般過去時。如：I saw that film three years ago.我三年前看了那部電影。含有 ago 時間狀語的直接引語變間接引語時，ago 應(yīng)變?yōu)?before。如：He said to me,“ I saw that film three years ago.” He told me that he had seen that film three years before.(2)指空間或位置，表示 “在前面 ”。如：Look at the page before.看前面一頁。四、4. 幾個需要注意的地方（ 1）ever before,單獨用

10、作狀語，表示 “以前 ”；ever since, 單獨用作狀語，表示“自從那時以來 ”；ever after, 單獨用作狀語，表示 “以后；后來 ”。（ 2）before long,單獨用作狀語，表示 “不久以后 ”，其中 long 為名詞，后面不接任何成分；可以用于各種時態(tài)。例如：Before long, he went to America. 不久，他就去了美國。 I hope to see you before long. 我希望不久后再見到你。long before：單獨用作狀語，表示“很久以前 ”，其中 before 為副詞，其后不接任何成分；一般用在過去時或過去完成時的句子里。表示

11、 “在之前很久 ”，其中 before 用作介詞或連詞，后可接名詞、動名詞、代詞或從句。 She said she had read the novel long before.她說她很久以前就讀過這部小說。 That happened long before. 那件事發(fā)生在很久以前。（3）when/ while/ if/ unless/ once/ even though 等引導(dǎo)從句時， 如果從句主語和主句的主語相同或為it,并且從句謂語含有be 動詞，則可以省略從句的主語和 be 動詞部分，形成 “when / while / if / unless /once /even though

12、+V -ing 或V-ed 分詞 ”結(jié)構(gòu)；但是 before 和 after 則不用這一句式，二者后只接動名詞或者完整的從句。 如：When (it is ) translated into English, the word means “newspaper”. 其中 it is 可省略 Before being operated on, he took some special medicine.其中 being operated on 為動名詞的被動式， being 不可省略。before 可以用作連詞 ,引導(dǎo)時間狀語從句 ?它用法靈活 ?譯法多變 ,是高考的一個重要考點 ?現(xiàn)對其用作連

13、詞時的用法加以總結(jié) ,希望對同學(xué)們有所幫助 ?1.【高考題例】 (加下劃線的選項為正確答案) (2006 四川 ) Why didnt you tell him about the meeting?He rushed out of the room_I could say a word. (2003 北 京 ) He made a mistake, but then he corrected thesituation_it got worse.2. before 作“才”解時 ,強調(diào)從句謂語動詞表示的動作發(fā)生得太慢或太晚 ?例如 :The bus driver almost knocked m

14、e down before he saw me. 那位公交車司機差一點把我撞倒 ,他才看到了我 ?The fire lasted about four hours before the firefighters were able to controlit. 大火持續(xù)了大約四個小時,消防隊員才把火控制住 ?【高考題例】 (加下劃線的選項為正確答案) (NMET 2004,) Several weeks had gone by_I realized the paintingwas missing. (2005 廣東 ) The American Civil War lasted four yea

15、rs_the Northwon in the end.A. after B. when C. before D. then3. before 可譯為 “趁”?“以免 ”?“以防 ”等?例如 :I ll do it now before I forget it趁.還沒有忘 ,我現(xiàn)在就把這事做了 ?Wed better finish the work in time before the boss scolds us我.們最好按時完成這項工作 ,免得挨老板的罵 ?4. before 可譯為 “(寧可 而)不愿 ”?例如 :Hed die before he apologizes to them他.

16、寧死也不向他們道歉 ?I d give up the plan before I turn to him for help我.寧可放棄計劃也不會向他求助 ?5. 注意 “It + be +一段時間 + before 從句 ”中主句和從句的時態(tài) ?該句式中 ,主句和從句的時態(tài)有兩種情況 :如果主句用一般將來時 ,則從句用一般現(xiàn)在時 ,意為 “多長時間以后某事即將發(fā)生 ”;如果主句用過去時 ,從句也用過去時 ,意為 “多長時間后某事才發(fā)生 ”?【高考題例】 (加下劃線的選項為正確答案) (2006 福建 ) How long do you think it will be_China sends

17、amanned spaceship to the moon?Perhaps two or three years.A. when B. until C. that D. before (2005 山東 ) It was some time_we realized the truth. A. when B. until C. since D. before練一練 :1. (2002 上 海 春 )It_long beforewe_the result oftheexperiment.A. will not be; will know B. is; will knowC. will not be;

18、 know D. is; know2. (2004 福建 ) Scientists say it may be five or six years_it is possibleto test this medicine on human patients.A. since B. after C. before D. when3. (2004 天津 ) It was evening _we reached the little townofWinchester.A. that B. until C. since D. before4. Why didnt you help the little boy?Oh, sorry. He had struggled to his feet _I ran over.A. before B. after C. until D. since5. Time passed quickly and three weeks went by _we knew it. A. before B. after C. when D. till6. She was such a proud person that she would die _she