一般現(xiàn)在時(shí)除主語是第三人稱單數(shù)時(shí)謂語動(dòng)詞要加s外

1、一般現(xiàn)在時(shí)除主語是第三人稱單數(shù)時(shí)謂語動(dòng)詞要加s外，一律用動(dòng)詞原形。例句： I go to school at 6 every morning. 每天早上我七點(diǎn)去上學(xué)。Summer follows spring. 春天之后是夏天。The sun rises in the east. 太陽從東方升起。I learned that the earth goes around the sun when I was in primary school. 我在小學(xué)就學(xué)過地球是圍繞太陽轉(zhuǎn)的。Pride goes before a fall. 驕者必?cái)　?#160;主要用于下面幾情況：1) 描述當(dāng)前

2、時(shí)間內(nèi)經(jīng)常出現(xiàn)、反復(fù)發(fā)生的動(dòng)作或存在的狀態(tài)。在這種情景中，句子常帶有表示頻率的時(shí)間狀語：always , everyday , often , once a week (month , year , etc.) , sometimes , seldom , usually等等，以表示句中的動(dòng)作或狀態(tài)是習(xí)慣性的、經(jīng)常性的。例如：They raise ducks as a sideline .他們以養(yǎng)鴨為副業(yè)。She doesn't often write to her family, only once a month. 她不常給家里寫信，僅一月一封而已。I cycle to work

3、every day .我每天騎自行車上班。It seldom rains here .這兒很少下雨。2）僅為了描述狀態(tài)、性質(zhì)、特征、能力等等。這里的目的是為了"描述現(xiàn)階段的動(dòng)作或狀態(tài)"，其重點(diǎn)"不是強(qiáng)調(diào)動(dòng)作發(fā)生的時(shí)間、或進(jìn)行的狀態(tài)"。例如：He can speak five foreign languages .他能說五種外語。That is a beautiful city .那是座美麗的城市。Changjiang River is one of the longest rivers in the world. 長江是世界上最長的河流之一。She ma

4、jors in music .她主修音樂。All my family love football .我全家人都喜歡足球。My sister is always ready to help others . 我妹妹總是樂于助人。3) 陳述客觀事實(shí)、客觀真理。顧名思義，客觀的情況是"沒有時(shí)間概念"的；也"不會(huì)在意動(dòng)作進(jìn)行的狀態(tài)"。例如：The sun rises in the east .日出東方。The earth goes around the sun .地球繞著太陽轉(zhuǎn)。Ten minus two is eight.十減二等于八。Light travel

5、s faster than sound .光的速度比聲音的速度快。The United States lies by the west coast of the Pacific Ocean. 美國位于太平洋西岸。4) 根據(jù)英文語法規(guī)定，當(dāng)主句的謂語動(dòng)詞是一般將來時(shí)，那么時(shí)間或條件狀語從句的謂語動(dòng)詞只能用一般現(xiàn)在時(shí)來表示將來要發(fā)生的動(dòng)作。例如：I'll tell him the news when he comes back. 他回來時(shí)，我將告訴他這個(gè)消息。If you take the job , they will talk with you in greater details.如

6、果你接受這份工作，他們將和你談?wù)劶?xì)節(jié)。用于一般現(xiàn)在時(shí)的副詞，除了上面提到的一些表示頻率的以外，常見的還有：now, today , nowadays等等。 1. 用于某些動(dòng)詞(tell, say, hear, learn, gather等)表示不確定的過去時(shí)間。如：I hear that he got married last month. 我聽說他上個(gè)月結(jié)婚了。Mary says you told her to come over here. 瑪麗說是你讓她到這兒來的。2. 當(dāng)要陳述一個(gè)客觀事實(shí)時(shí)，有時(shí)即使有過去時(shí)間狀語也可用一般現(xiàn)在時(shí)。如：The story is set in

7、the summer of 1937. 故事的背景是1937年夏天。The story begins in the year 1937. 故事開始于1937年。 一般過去時(shí)用動(dòng)詞的過去式構(gòu)成，即在動(dòng)詞原形后加ed。例句：He was here just now. 他剛才還在這里。What did you do yesterday? 你昨天做了什么事？We often played together when we were children. 我們小時(shí)候常在一起玩。He used to smoke a lot, but he doesnt now. 他過去經(jīng)常抽煙，但現(xiàn)在不抽了。Wh

8、enever we were in trouble, he would help us. 每當(dāng)我們遇到困難，他都會(huì)幫助我們。At that time she was very good at English. 那時(shí)她英語學(xué)得很好。He said he would wait until they came back. 主要是用來描述在過去某個(gè)時(shí)候發(fā)生的動(dòng)作或存在的狀態(tài)。它也可以用來表示在過去某段時(shí)間里經(jīng)常發(fā)生的習(xí)慣性動(dòng)作。這一點(diǎn)在表達(dá)意義上與一般現(xiàn)在時(shí)相同，只是所在的時(shí)間區(qū)域不同而已。由于它的主要作用如此，所以在使用一般過去時(shí)的句子里常常有一個(gè)意義較具體的過去時(shí)間狀語。這也是它與現(xiàn)在完

9、成時(shí)的最大區(qū)別之一。一般過去時(shí)由謂語動(dòng)詞的過去式表示，也就是說動(dòng)詞詞末要加-ed（除不規(guī)則動(dòng)詞外）。常和一般過去時(shí)連用的過去時(shí)間狀語有：last night (week ,month , year , century , etc.) , yesterday , the day before yesterday , yesterday morning ( afternoon , evening ) , in 1999 , two hours ago ( one week ago , tree years ago , )等等。使用一般過去時(shí)，在某種意義上說就是要強(qiáng)調(diào)動(dòng)作或狀態(tài)發(fā)生或存在于過去的某個(gè)

10、時(shí)候。"過去"的時(shí)間概念有兩層意思：一是指"現(xiàn)在某個(gè)時(shí)間"以前的時(shí)間；二是指"說話、寫文章的那個(gè)時(shí)間點(diǎn)"以前的時(shí)間，在這個(gè)意義上，"現(xiàn)在的那個(gè)時(shí)間點(diǎn)"是很小很小的，甚至于小到無法量化的程度。例如：He got his driving license last month. 他上個(gè)月拿到了駕照。-Where's Jim? 吉姆在哪里？-He just went out.他剛剛出去。 (1) 在賓語從句中，由于時(shí)態(tài)呼應(yīng)的關(guān)系，可用一般過去時(shí)表示現(xiàn)在：I didnt know you were here

11、. 我不知道你在這兒。(were實(shí)際上指現(xiàn)在)I didnt know you were so busy我沒想到你這么忙。(were實(shí)際上指現(xiàn)在)(2) 表示客氣委婉的現(xiàn)在：I wondered if you were free this evening. 不知您今晚是否有空。I thought you might like some flowers. 我想您也許想要些花。【注】能這樣有的動(dòng)詞主要限于want, wonder, think, hope, intend等少數(shù)動(dòng)詞。(3) 用于某些特殊結(jié)構(gòu)中表示現(xiàn)在：Its time we started. 我們?cè)搫?dòng)身了。I wish I knew

12、 his name. 要是我知道他的名字就好了。Id rather you lived closer to us. 我希望你能住得離我們近點(diǎn)?！咀ⅰ吭撚梅ㄖ饕糜?its time, I wish, Id rather, if only, as if, as though 等少數(shù)結(jié)構(gòu)后接從句的情形，其中有些結(jié)構(gòu)后面的句子還可用一般過去時(shí)表示將來：Id rather you came next Monday. 我寧愿你下周星期一來。另外表主觀想法的虛擬條件句也用一般過去時(shí)表示現(xiàn)在：If I had the money now Id buy a car. 假若我現(xiàn)在有錢，我就買輛小汽車。 

13、;一般將來時(shí)由 will 加動(dòng)詞原形構(gòu)成，當(dāng)主語是第一人稱時(shí)，也可以用 shall 加動(dòng)詞原形。例如：Telephone me this evening. Ill be at home. 今晚給我打電話，我會(huì)在家。Ill (shall/will) do a better job next time. 下次我要干得好些。The car wont start. 車開不了啦。Oil and water will not mix. 油和水沒法混在一起。 主要用來描述將要發(fā)生的動(dòng)作或存在于未來的情況。這里所說的“將來時(shí)間”是指“說話、寫文章那一刻以后的時(shí)間”。它的表示方法主要有如下幾種：1）s

14、hall / will + 動(dòng)詞原形這種表示方法是說，動(dòng)作在現(xiàn)在或目前還未發(fā)生，要在將來的某個(gè)時(shí)間內(nèi)發(fā)生；它沒有主觀性，是“純粹的將來動(dòng)作”。例如：I shall / will not be free tomorrow .我明天沒空。He will arrive here this evening .他今晚抵達(dá)這里。2) be( am / is / are ) + going +不定式這種表示方法主要是說明 A）“說話人的意圖、打算”；B）“某種可能性”。例如：A) He is going to spend his holidays in London . 他打算在倫敦度假。Who is go

15、ing to speak first? 誰先發(fā)言？B) It is going to rain soon .馬上要下雨了。Is he going to collect any data for us? 他會(huì)幫我們收集資料嗎？If you go to New Zealand, you are going to like the place. 如果你去新西蘭，你會(huì)喜歡上那個(gè)地方的。3) be( am / is / are ) + 不定式表示方法描述兩鐘情況：按計(jì)劃安排要發(fā)生的動(dòng)作，這個(gè)動(dòng)作發(fā)生的時(shí)間一般不會(huì)很遠(yuǎn)； 要求或命令他人做某事。例如：A) The new bridge is to open

16、 to traffic in three days. 新橋三天后通車。The factory is to go into production before National Day. 這家工廠國慶節(jié)前投產(chǎn)。B) You are not to bring any mobile communication means into the exam-room . 任何移動(dòng)通訊工具都不得帶入考場。You are to stay home until your mother comes back. 你媽回來之前你不要出去。4) 用一般現(xiàn)在時(shí)或現(xiàn)在進(jìn)行時(shí)（限于某些動(dòng)詞）表示按計(jì)劃安排要發(fā)生的事。主要強(qiáng)調(diào)“

17、按計(jì)劃安排要發(fā)生的事”。例如：Do you get off at the next stop? 你下一站下車嗎？The plane takes off at 11:00 a.m. 那架飛機(jī)上午十一點(diǎn)起飛。Mr. Reider is leaving for New York next week. 里德先生下周動(dòng)身去紐約。 1. “be+不定式”：表示命令、安排、傾向或必須、義務(wù)等。如：She is to play Juliet. 她扮演朱麗葉。You are to make the necessary changes. 你要做出必要的改變。2. “be about to + 不定式”：

18、表示即將發(fā)生的動(dòng)作，有“即將”的意思，但不能和具體的時(shí)間狀語連用。如：The package is about to come unwrapped. 那個(gè)包快散開了。3. “be going + 不定式”：表示按計(jì)劃或安排打算去做某事，或表示有跡象表明要發(fā)生某事。如：We are going to call her this evening. 我們打算今晚給她打電話。My sisters going to have a baby this summer. 我姐姐今年夏天要生孩子。4. 用現(xiàn)在進(jìn)行時(shí)表示將來：主要表示按規(guī)定或時(shí)間預(yù)計(jì)要發(fā)生的事。如：The students are leaving

19、 on Sunday. 學(xué)生們星期日出發(fā)。Were having a party next week. 我們下星期將開一個(gè)晚會(huì)。5. 用一般現(xiàn)在時(shí)表示將來：表示按規(guī)定或時(shí)間預(yù)計(jì)要發(fā)生的事。如：We have a holiday tomorrow. 我們明天放假。The train leaves at 10:04 this evening. 火車今晚10:04分開。 現(xiàn)在進(jìn)行時(shí)由 am/is/are 加現(xiàn)在分詞構(gòu)成。       例句：        The

20、yre having a meeting. 他們?cè)陂_會(huì)。Im studying at an evening school. 我在上夜校。Mike is coming home on Thursday. 邁克星期四回來。Theyre having a party next week. 下星期他們將開一個(gè)晚會(huì)。Youre always interrupting me! 你老打斷我的話!(抱怨)My father is always losing his car keys. 我爸老丟車鑰匙。(不滿)Shes always helping people. 她老是幫助別人。(贊揚(yáng))主要用來描述“說話、寫

21、文章的當(dāng)刻”正在發(fā)生的動(dòng)作，或是“現(xiàn)階段”一直在進(jìn)行的動(dòng)作。它適用于下面的情況：1）“說話、寫文章的當(dāng)刻”正在發(fā)生的動(dòng)作。例如：They are having a football match .他們正在賽足球。She is writing her term paper. 她正在寫學(xué)期論文。Someone is asking for you on the phone. 有人找你聽電話。2）“現(xiàn)階段”一直在進(jìn)行的動(dòng)作。這種情況并不是說某個(gè)動(dòng)作在說話的那會(huì)兒正在發(fā)生，而是說某個(gè)動(dòng)作在當(dāng)前一段時(shí)間內(nèi)一直在進(jìn)行著，或是重復(fù)地發(fā)生著。例如：He is preparing for CET Band Six

22、. 他在為大學(xué)英語六級(jí)考試作準(zhǔn)備。How are you getting along with your new job？ 你那份新工作干得怎么樣？3）表示說話人的情感，如：贊許、批評(píng)；喜歡、厭惡等。這時(shí)的動(dòng)作并不是正在發(fā)生或進(jìn)行，而是表示經(jīng)常性，相當(dāng)于“一般現(xiàn)在時(shí)”所描述的情況。例如：He is always thinking of others , not of himself . （表示贊許）他總是為他人著想，而不為自己。She is often doing well at school. （表示滿意）她在學(xué)校學(xué)習(xí)挺不錯(cuò)的。Are you feeling better today? （表

23、示親切）你今天覺得好一些嗎？One of my roommates is constantly leaving things about.（表示不滿）我的一個(gè)室友老是亂扔?xùn)|西。Some sellers are often knocking at our door and promoting their products to us .（表示不喜歡） 有些推銷員老是敲我家的門,向我們推銷他們的產(chǎn)品。4）表示在近期按計(jì)劃或安排要發(fā)生的動(dòng)作,用于這種情況僅限于少量的動(dòng)詞，如：go , come , leave ,arrive , see , have , lunch( 吃午飯 ) , return,

24、 dine ( 進(jìn)餐，尤指晚餐 ) , work , sleep , stay , play , do , wear( 穿，戴 ) 等。例如：I'm dinning out with my friends this evening. 今晚我將和朋友在外面吃飯。An American professor is giving a lecture this afternoon. 今天下午一位美國教授要來作報(bào)告。We are having a holiday next Wednesday. 下周三我們放假。Are you staying here till next week? 你要在這兒呆到

25、下星期嗎？ 現(xiàn)在進(jìn)行時(shí)表將來，主要表示按計(jì)劃或安排要發(fā)生的動(dòng)作：Im leaving tomorrow. 我明天走。Theyre getting married next month. 他們下個(gè)月結(jié)婚?，F(xiàn)在進(jìn)行時(shí)與一般現(xiàn)在時(shí)均可表示將來，區(qū)別是：用現(xiàn)在進(jìn)行時(shí)表示將來，其計(jì)劃性較強(qiáng)，并往往暗示一種意圖；而一般現(xiàn)在時(shí)表示將來，則其客觀性較強(qiáng)，即通常被視為客觀事實(shí)，多指按時(shí)刻表或規(guī)定要發(fā)生的情況：Im not going out this evening. 今晚我不準(zhǔn)備出去。What time does the train leave? 火車什么時(shí)候開? 過去進(jìn)行時(shí)主要表示在過去

26、的某個(gè)時(shí)間點(diǎn)上正在發(fā)生、進(jìn)行的動(dòng)作。由于它的定義是表示在過去的某個(gè)時(shí)間點(diǎn)上正在發(fā)生、進(jìn)行的動(dòng)作，所以，句子常帶有一個(gè)表示“過去某個(gè)時(shí)間點(diǎn)”的狀語。這個(gè)狀語可能是短語，詞組，或是一個(gè)從句。也可能是通過上下文來表達(dá)這層意思。過去進(jìn)行時(shí)主要用于下面的情景中：1）表示在過去某時(shí)刻正在進(jìn)行的動(dòng)作，例如：At this moment yesterday, I was packing for camp.昨天這個(gè)時(shí)候，我正在收拾東西去露營。When I came to see her last time, she was writing an article.上次我來看她的時(shí)候，她正在寫一篇文章。What w

27、ere you doing at eight last night ? 昨晚八點(diǎn)鐘你在做什么？2）用于故事的開頭，交代故事發(fā)生的背景情況。過去進(jìn)行時(shí)所描述的動(dòng)作是“正在進(jìn)行”，所以，在這種情景中用“過去進(jìn)行時(shí)”可以給讀者一種“動(dòng)感”，從而能使文章更加生動(dòng)活潑。例如：One night, he was typing in his study . Suddenly , a man broke into his house and cut off the electricity .一天晚上，他正在書房里打字。突然，一個(gè)人闖進(jìn)屋來，切斷了電源3)（僅限少數(shù)動(dòng)詞）表示在過去的未來時(shí)間要發(fā)生的動(dòng)作。例如：

28、When National Day was coming near , they began to make a plan for the holiday .國慶節(jié)即將來臨的時(shí)候，他們開始制訂度假計(jì)劃。She told me that she was going to Hainan for her holiday. 她告訴我她將去海南度假。My friend said to me that he was lunching with one of his customers that day .我朋友對(duì)我說，他今天要與他的一位客戶一塊兒吃午飯。We left there when it'

29、s getting dark. 天快黑的時(shí)候，我們離開了那兒。 用過去進(jìn)行時(shí)表示現(xiàn)在，主要是為了使語氣委婉、客氣。如：I was wondering if you could give me a lift. 我不知你能否讓我搭一下車。We were hoping you would stay with us. 我們很希望你能跟我們住在一起。How much did you want to spend, sir? 先生，您打算花多少錢？注：一般過去時(shí)也有類似用法，但比較而言，用過去進(jìn)行時(shí)顯得更客氣，更不肯定。 過去完成時(shí)由 had 加動(dòng)詞的過去分詞構(gòu)成。例句：She said

30、 she had never been to Paris. 她說她從未去過巴黎。When the police arrived, the thieves had run away. 警察到達(dá)時(shí)，小偷們?cè)缇团芰?。By the time he was twelve, Edison had begun to make a living by himself. 到了十二歲那年，愛迪生開始自己謀生。 一、過去完成時(shí)的概念與結(jié)構(gòu)特點(diǎn)概念：過去完成時(shí)表示在過去某一時(shí)間或動(dòng)作之前已經(jīng)發(fā)生或完成了的動(dòng)作，即"過去的過去（ past-in-the-past ）"。-|- |-|-&g

31、t;那時(shí)以前          那時(shí)               現(xiàn)在構(gòu)成：過去完成時(shí)由"助動(dòng)詞 had + 過去分詞"構(gòu)成，其中 had 通用于各種人稱。They had already had breakfast before they arrived at the hotel.She had finished writing the comp

32、osition by 10 ：00 this morning.二、過去完成時(shí)的判斷依據(jù)1. 由時(shí)間狀語來判定一般說來，各種時(shí)態(tài)都有特定的時(shí)間狀語。與過去完成時(shí)連用的時(shí)間狀語有：（ 1 ） by + 過去的時(shí)間點(diǎn)。如： I had finished reading the novel by nine o'clock last night. （ 2 ） by the end of + 過去的時(shí)間點(diǎn)。如： We had learned over two thousand English words by the end of last term.（ 3 ） before + 過去的

33、時(shí)間點(diǎn)。如： They had planted six hundred trees before last Wednesday.2. 由"過去的過去"來判定。過去完成時(shí)表示"過去的過去"，是指過去某一動(dòng)作之前已經(jīng)發(fā)生或完成的動(dòng)作，即動(dòng)作有先后關(guān)系，動(dòng)作在前的用過去完成時(shí)，在后的用一般過去時(shí)。這種用法常出現(xiàn)在：（ 1 ）賓語從句中當(dāng)賓語從句的主句為一般過去時(shí)，且從句的動(dòng)作先于主句的動(dòng)作時(shí)，從句要用過去完成時(shí)。在told, said, knew, heard, thought等動(dòng)詞后的賓語從句。如：She said that she had seen the

34、 film before. （ 2 ）狀語從句中 在時(shí)間、條件、原因、方式等狀語從句中，主、從句的動(dòng)作發(fā)生有先后關(guān)系，動(dòng)作在前的，要用過去完成時(shí)，動(dòng)作在后的要用一般過去時(shí)。如：When I got to the station, the train had already left.After he had finished his homework, he went to bed.注意： before, after 引導(dǎo)的時(shí)間狀語從句中，由于 before 和 after 本身已表達(dá)了動(dòng)作的先后關(guān)系，若主、從句表示的動(dòng)作緊密相連，則主、從句都用一般過去時(shí)。如：Where

35、did you study before you came here?After he closed the door, he left the classroom.（ 3 ）表示意向的動(dòng)詞，如hope, wish, expect, think, intend, mean, suppose等，用過去完成時(shí)表示"原本，未能"We had hoped that you would come, but you didn't.3. 根據(jù)上、下文來判定。I met Wang Tao in the street yesterday. We hadn't seen eac

36、h other since he went to Beijing.三、過去完成時(shí)的主要用法1. 過去完成時(shí)表示一個(gè)動(dòng)作或狀態(tài)在過去某一時(shí)間或動(dòng)作之前已經(jīng)完成或結(jié)束，即發(fā)生在"過去的過去"。如：When I woke up, it had stopped raining.我醒來時(shí)，雨已經(jīng)停了。（主句的動(dòng)作發(fā)生在"過去的過去"）2. 過去完成時(shí)是一個(gè)相對(duì)的時(shí)態(tài)，表示的是"過去的過去"，只有和過去某一時(shí)間或某一動(dòng)作相比較時(shí)才使用它。如：He told me that he had written a new book. (had writt

37、en 發(fā)生在 told 之前 )3. 過去完成時(shí)需要與一個(gè)表示過去的時(shí)間狀語連用，它不能離開過去時(shí)間而獨(dú)立存在。此時(shí)多與 already ， yet ， still ， just ， before ， never 等時(shí)間副詞及 by ， before ， until 等引導(dǎo)的短語或從句連用。如：Before she came to China, Grace had taught English in a middle school for about five years.Peter had collected more than 300 Chinese stamps by the time

38、he was ten.4. 過去完成時(shí)表示某一動(dòng)作或狀態(tài)在過去某時(shí)之前已經(jīng)開始，一直延續(xù)到這一過去時(shí)間，而且動(dòng)作尚未結(jié)束，仍然有繼續(xù)下去的可能。如： By the end of last year, he had worked in the factory for twenty years.      （ had worked 已有了 20 年，還有繼續(xù)進(jìn)行下去的可能）四、過去完成時(shí)與現(xiàn)在完成時(shí)的區(qū)別現(xiàn)在完成時(shí)表示的動(dòng)作發(fā)生在過去，但側(cè)重對(duì)現(xiàn)在產(chǎn)生的結(jié)果或造成的影響，與現(xiàn)在有關(guān)，其結(jié)構(gòu)為"助動(dòng)詞 have (has) + 過去分詞&q

39、uot;；過去完成時(shí)則是一個(gè)相對(duì)的時(shí)態(tài)，它所表示的動(dòng)作不僅發(fā)生在過去，更強(qiáng)調(diào)"過去的過去"，只有和過去某時(shí)或某動(dòng)作相比較時(shí)，才用到它。試比較：I have learned 1000 English words so far.到目前為止我已經(jīng)學(xué)會(huì)了 1000 個(gè)英語單詞。I had learned 1000 English words till then.到那時(shí)為止我已經(jīng)學(xué)會(huì)了 1000 個(gè)英語單詞。- I'm sorry to keep you waiting. 對(duì)不起，讓你久等了。- Oh, not at all. I have been here only a

40、few minutes.沒什么，我只等了幾分鐘。（"等"的動(dòng)作從過去某一時(shí)間點(diǎn)持續(xù)到現(xiàn)在）- John returned home yesterday. 約翰昨天回到家的。- Where had he been?他去哪兒了？（答語中使用過去完成時(shí)是指約翰在 returned home 之前去了哪些地方，即"過去的過去"）五、過去完成時(shí)與一般過去時(shí)的區(qū)別雖然這兩種時(shí)態(tài)都表示過去發(fā)生的動(dòng)作或存在的狀態(tài)，但在使用時(shí)應(yīng)注意以下幾點(diǎn)：1. 時(shí)間狀語不同：過去完成時(shí)在時(shí)間上強(qiáng)調(diào)"過去的過去"；而一般過去時(shí)只強(qiáng)調(diào)過去某一特定的時(shí)間。試比較：They

41、 had arrived at the station by ten yesterday.They arrived at the station at ten yesterday.2. 在沒有明確的過去時(shí)間狀語作標(biāo)志時(shí)，謂語動(dòng)詞動(dòng)作發(fā)生的時(shí)間先后須依據(jù)上下文來判斷：先發(fā)生的用過去完成時(shí)，后發(fā)生的則用一般過去時(shí)。如：She was very happy. Her whole family were pleased with her, too. She had just    won the first in the composition competition.3

42、. 當(dāng)兩個(gè)或兩個(gè)以上接連發(fā)生的動(dòng)作用 and 或 but 連接時(shí)，按時(shí)間順序，只需用一般過去時(shí)來代替過去完成時(shí)；另外，在 before ， after ， as soon as 引導(dǎo)的從句中，由于這些連詞本身已經(jīng)表示出時(shí)間的先后，因此也可以用過去時(shí)來代替過去完成時(shí)。如：He entered the room, turned on the light and read an evening paper.I (had) called her before I left the office.過去完成時(shí)可表示過去未曾實(shí)現(xiàn)的想法和打算，通常連用的動(dòng)詞是 want, think, hope, plan,

43、 mean, expect, intend, suppose 等：I had meant to come, but something happened. 我本想來，但有事就沒有來。I had intended to speak, but time did not permit. 我本想發(fā)言，但時(shí)間不允許。We had hoped that you would come to see us, but you didnt. 我們本想你來看我們的，但你沒有來?，F(xiàn)在完成時(shí)由 have 加動(dòng)詞的過去分詞構(gòu)成，主語是第三人稱單數(shù)時(shí)，要將 have 改為 has。例句：I have seen the fi

44、lm already. 我已經(jīng)看過那部電影了。(現(xiàn)在我知道電影的內(nèi)容了。)Have you seen my bag? 你看到我的手提包了嗎? (你知道它在哪里? )She has been a dancer for ten years. 她已當(dāng)了十年的舞蹈演員了。Weve planted thousands of trees in the past few years. 過去幾年我們種了成千上萬棵樹。對(duì)于初接觸現(xiàn)在完成時(shí)的人來說，往往會(huì)產(chǎn)生一種茫然，因?yàn)樗坪跖c一般過去時(shí)相似。那就是，這兩種時(shí)態(tài)描述的動(dòng)作都始于過去。其實(shí)不然，現(xiàn)在完成時(shí)主要表示，發(fā)生在過去的動(dòng)作延續(xù)到現(xiàn)在剛剛完成、或許還要延續(xù)

45、；側(cè)重于這個(gè)動(dòng)作對(duì)現(xiàn)在帶來的結(jié)果、產(chǎn)生的影響、積累的總和等等。而一般過去時(shí)則只不過是表示動(dòng)作發(fā)生在過去的什么時(shí)候。弄清了這一區(qū)別，就很容易理解現(xiàn)在完成時(shí)了。它主要適用于下面的幾種情況：1）表示截止現(xiàn)在業(yè)已完成的動(dòng)作By now, I have collected all the data that I need .到現(xiàn)在為止，我已收集到了我所需的全部資料。She has read 150 pages today .她今天已看了150頁。We haven't met for many years .我們已多年沒見了。They have developed a new product .他

46、們研制成功了一種新產(chǎn)品。2）表示發(fā)生在過去而對(duì)現(xiàn)在產(chǎn)生影響、帶來結(jié)果的動(dòng)作Have you had your dinner? 你吃晚飯了嗎？She has been to the United States. 她已去美國了。You have grown much taller.你長高了許多。3）表示過去發(fā)生的動(dòng)作持續(xù)到現(xiàn)在，并可能還要延續(xù)It has been five years since he joined the army .他參軍五年了。They have learned English for eight years .他們已學(xué)了八年的英語了。So far we've on

47、ly discussed the first five chapters.至今我們還只討論了前五章。幾點(diǎn)注意1)一個(gè)句子應(yīng)該用什么時(shí)態(tài)只能取決于它需要表達(dá)的意思，以及它所處的語言環(huán)境。例如：He speaks English .（一般現(xiàn)在時(shí)，說明動(dòng)作發(fā)生的經(jīng)常性。）He spoke English when he was in New Zealand .（一般過去時(shí)，說明動(dòng)作發(fā)生的時(shí)間。）He is speaking English.（現(xiàn)在進(jìn)行時(shí)，說明動(dòng)作正在進(jìn)行。）He has spoken English for three years since he came to the USA.（

48、現(xiàn)在完成時(shí)，這里說明動(dòng)作的總和。）He has been speaking English since he came to the USA. （現(xiàn)在完成進(jìn)行時(shí)，強(qiáng)調(diào)動(dòng)作的連續(xù)性。）2）在含有時(shí)間狀語從句或條件狀語從句的主從復(fù)合句中，如果主句的謂語動(dòng)詞是一般將來時(shí)，那么從句的謂語動(dòng)詞就只能用一般現(xiàn)在時(shí)來表示將來時(shí)；如果主句的謂語動(dòng)詞是過去將來時(shí)，那么從句的謂語動(dòng)詞就只能用一般過去時(shí)來表示過去將來時(shí)。例如：I will not play tennis if it rains tomorrow.I would not play tennis if it rained the next day.3)

49、 有些動(dòng)詞表示無法持續(xù)的動(dòng)作，它們一般不宜用于進(jìn)行時(shí)態(tài)中。這類動(dòng)詞常見的有：be , believe , consist , find , forget , hate , have , hope , hear , know , like , love , notice , prefer , remember , see , seem , smell , suggest , taste , understand , want , wish , sit down , stand up 等等。Be動(dòng)詞若是用于進(jìn)行時(shí)態(tài)，可表示暫時(shí)、短暫的情況或表現(xiàn)。例如：Tom is being a good boy

50、 today .湯姆今天很乖。He is being childish .他這樣做是耍孩子氣。You are not being modest .你這樣說不太謙虛。4）關(guān)于現(xiàn)在完成時(shí)的時(shí)間狀語問題A. 凡是"完成時(shí)態(tài)"都表示，不知道也不管動(dòng)作發(fā)生的具體時(shí)間, 所以在使用現(xiàn)在完成時(shí)的句子里，不可以帶有表示具體過去時(shí)間的狀語，如：yesterday , last week ( month , year , etc. ) , two weeks ago , in 1999等；但常和有些副詞連用，如： just , before , already , often , never

51、, ever , notyet , always等等。B. 在以when提問的特殊疑問中不能用現(xiàn)在完成時(shí)。另外，ago不能用于現(xiàn)在完成時(shí)的句子里，因?yàn)樗硎緩默F(xiàn)在算起的以前某個(gè)時(shí)間，屬于表示具體過去時(shí)間的狀語。但是可以用before 來表示"以前"的意義，因?yàn)樗槐硎?quot;以前"，而不知什么時(shí)候的以前。C. 如果是不表示連續(xù)性的動(dòng)詞用于現(xiàn)在完成時(shí)的句子，不可以和以for表示的"一段時(shí)間"的狀語連用。在這種情況下，應(yīng)該用"It has been ；since"的句式來表達(dá)。如：He has joined the army

52、 for five years. （錯(cuò)誤）It has been five years since he joined the army.（正確） 能與現(xiàn)在完成時(shí)連用詞語很多，如副詞just, already, yet, before, ever, recently 等，但下面是一些典型而且重要的例子：(1) since(自從)：不管用作介詞、連詞還是副詞, 句子(主句)謂語通常都用現(xiàn)在完成時(shí)：I havent seen her since last week. 自上周以來我一直未見過她。Where have you been since I last saw? 自我上次見到你之后你

53、到哪里去了?【注】有時(shí)可用其他時(shí)態(tài)的情況，但須注意： 對(duì)于某些表示狀態(tài)的動(dòng)詞(如 seem 等)，或因語義等方面的原因，有時(shí)可能用一般現(xiàn)在時(shí)比較現(xiàn)在完成時(shí)更合適：It seems like years since we last met. 我們似乎幾年未見面了。Since when does the $42 plus $5 service charge come to $48? 從什么什候開始42元加5元的服務(wù)費(fèi)等于48元了? 若不是指從過去持續(xù)到現(xiàn)在，而是指從較遠(yuǎn)的過去持續(xù)到在一個(gè)較近的過去，則用過去完成時(shí)：Yesterday he told me that he hadnt eaten anything since Tuesday. 他昨天告訴我自星期二以來他一直未吃任何東西。(指從星期二至昨天未吃東西) 表示時(shí)間長度時(shí)，通常用一般現(xiàn)在時(shí)代替現(xiàn)在完成時(shí)：Its ten years since he left here. 他離開這兒已10年了。(2) so far(到目前為止)：So far there has been no bad news. 到現(xiàn)在為止還沒有什么壞消息。We havent had any trouble so far. 到目前為止，我們還沒有遇到任何麻煩。  (3)