八年級英語下冊 Unit 1 Past and Present語法解析教案 （新版）牛津版

1、Unit 1 Past and present一. 教學內(nèi)容：Unit 1 Past and present Grammar二. 教學目標：掌握Unit1的語法: Present perfect tense 現(xiàn)在完成時的用法（一）基本概念1、定義現(xiàn)在完成時用來表示之前已發(fā)生或完成的動作或狀態(tài)，但它的影響現(xiàn)在還存在；也可表示持續(xù)到現(xiàn)在的動作或狀態(tài)。2、構(gòu)成： have (has) +過去分詞。規(guī)則變化的過去分詞與過去式的變化一樣，在動詞詞尾加ed; 不規(guī)則變化的過去分詞見不規(guī)則動詞表，需要同學們記憶。3、句型：現(xiàn)以see the film為例將現(xiàn)在完成時的肯定句，否定句和疑問句列表如下：肯定句：

2、I/You/We/They have seen the film. He/She /It has seen the film.否定句：I/You/We/They have not/ havent seen the film.He/ She/It has not/hasnt seen the film.疑問句：Have I/you/they seen the film? Yes, you/ we/I/they have. No, you/ we/I/they havent. Has he/she/it seen the film? Yes, he/ she/ it has. No, he/ sh

3、e/ it hasnt.（二）用法：現(xiàn)在完成時既涉及過去，又聯(lián)系現(xiàn)在。用法一：表示過去發(fā)生或已經(jīng)完成的某一動作對現(xiàn)在造成的影響或結(jié)果。常與just（剛剛），already（已經(jīng)），never（從來沒有），ever（曾經(jīng)），before（以前），yet（仍然），once（一次），twice（兩次），many times（很多次），how many times（多少次），so far（迄今為止），during the past（last）three years（最近三年來）等連用。 副詞的位置：just常用于肯定句中，放在have / has后，He has just come .never表示否

4、定, 放在have / has后, He has never visited the Great Wall.ever用于疑問句中,句型為: Have / Has主語ever 過去分詞？“曾經(jīng)過嗎？”用于詢問某人過去的經(jīng)歷。Have you ever been to the farm？before用于句末，The woman has never heard of that before.yet 用于句末或not 之后. Has the train arrived yet? No, not yet.already用于肯定句, have / has 之后或句末.We have already fin

5、ished it.so far用于句首或句末. So far, we have visited the moon.用法二：表示過去已經(jīng)開始，一直延續(xù)到現(xiàn)在的動作或狀態(tài)。時間狀語有：（三）現(xiàn)在完成時態(tài)中可以和表示一段時間的狀語（for，since，how long, all ones life）連用的動詞必須是表示延續(xù)的情況或動作的動詞，即延續(xù)性動詞。如：be，have，know，live，work，study，learn，teach，keep，speak，talk，draw，wait，wear，walk，sleep，drive，write，do，clean等。I have been a tea

6、cher for nearly 20 years. How long has he lived here?（四）延續(xù)性動詞的現(xiàn)在完成時可和包括“現(xiàn)在”在內(nèi)的（到說話時仍未結(jié)束）表示一段時間的狀語連用。如this morning，today，this week，these daysHe has been to Beijing three times this year.He has written two letters this morning.（說話時間在上午）He wrote two letters this morning.（說話時間在下午或晚上）（五）英語中還有一些動詞的意義決定它們所

7、表示的動作不能延續(xù)，只是一瞬間就結(jié)束的動作,這類動詞叫做“非延續(xù)性動詞”，常見的有：come，go，arrive，reach，see，hear，close，open，leave，begin，start，lose，buy，fall，join，die，get up，become，borrow，lend，find，finish，receive等。這些動詞可用于現(xiàn)在完成時，說明某個動作的結(jié)果還存在，但不能和表示一段時間的狀語（how long，for，since）連用。He has come back.（）He has come back for two hours.（） 但在否定句中，非延續(xù)性動詞也

8、可用表示一段時間的狀語來修飾，如I havent heard from my father for a long time. We havent seen him since 1999.（六）當終止性動詞（非延續(xù)性動詞）與表示一段時間的狀語（how long，since，for，all ones life）相矛盾時,改正錯句的方法有如下幾種:（1）用副詞ago把現(xiàn)在完成時的句子改為一般過去時.He has come back for two weeks.（錯）改為: He came back two weeks ago.（正）I have lost my bike for ten days.

9、（錯）改為: I lost my bike ten days ago. （正）（2）用“It is / has been時間since一般過去時態(tài)”句型來改寫。He has joined the League for 3 years. （錯）It is 3 years since he joined the League.（正）I have bought the book for 5 days. （錯）It is 5 days since I bought the book. （正）He has died for 20 years. （錯）It is 20 years since he die

10、d. （正）（3）用“時間has passedsince一般過去時態(tài)”句型來改寫。He has left home for 20 years. 改為: Twenty years has passed since he left home.He has lost his pen for 2 days. 改為: Two days has passed since he lost his pen.（4）用系表結(jié)構(gòu)來改寫.He has died for 20 years. 改為: He has been dead for 20 years.The factory has opened since 19

11、99. 改為: The factory has been open since 1999.How long has he left? 改為: How long has he been away?（5）用相應(yīng)的延續(xù)性動詞替代非延續(xù)性動詞。He has bought the book for two weeks. 改為: He has had the book for two weeks.常見的相應(yīng)轉(zhuǎn)換形式如下:borrow / lendkeep, buyhave, finish / endbe over, arrive /come / go / move / reach /get tobe in

12、 /at / be here /be there, begin / startbe on , openbe open , closebe closed, diebe dead , leavebe away（from）, go to schoolbe in school / be a student, get upbe up, fall asleepbe asleep , fall illbe ill, get to knowknow, losebe lost, becomebe, return / come back / get backbe back, joinbe in / be amem

13、ber, join the armybe in the army /be a soldier, receive / get a letterhave a letter , catch / get a coldhave a cold, begin to studystudy 他參軍已有三年。He has joined the army for three years.（錯）改為：He has been in the army for three years / since three years ago.He has been a soldier for three years / since

14、three years ago.He joined the army three years ago.It is three years since he joined the army.Three years has passed since he joined the army.（1）He came to our village two years ago.=He our village since two years ago.（2）He left home three days ago. =He home for 3 days.（3）I bought the watch 2 weeks

15、ago. =I the watch since 2 weeks ago.（4）It is 5 days since I borrowed the book. =I the book for 5 days.（5）The film has begun. = The film for half an hour.（6）I got to know him 10 years ago. =I him for 10 years.（7）There is a factory. =There a factory for 20 years.（8）Our school opened in 1960. =Our scho

16、ol since 1960.（七）現(xiàn)在完成時中應(yīng)注意的幾個問題1. have been to 和have gone to的區(qū)別 have been to 強調(diào)“去過”，現(xiàn)已不在那里，如：He has been to the USA three times.他到美國去過三次。（過去“到美國”，現(xiàn)在已“不在美國”）have gone to主要強調(diào)的是“去了”，現(xiàn)在人不在說話的現(xiàn)場，如：Wheres your mother? 你媽媽在哪？She has gone to the hospital. 她去醫(yī)院了。2. have been to 和have been in的區(qū)別 have been to強

17、調(diào)人“已回到原地”，后面可接表示“次數(shù)”的狀語。eg. She has been to Shanghai only once.How many times has he been there? Hes been there many times.have been in表示某人“已在某地停留一段時間，現(xiàn)仍在那里”，其后常帶表示一段時間的狀語。eg. They have been at the bus stop for half an hour.他們在車站呆了半小時。（現(xiàn)在仍然在車站）We have been in Xian for two weeks.我們在西安呆了兩個多星期。（現(xiàn)仍在西安）H

18、ow long have they been in China?他們在中國呆了多長時間了？（仍在中國）（八）如何通過與一般過去時做比較,進一步掌握現(xiàn)在完成時?一般過去時和現(xiàn)在完成時的動作都發(fā)生在過去,但意義卻不同.如: I learned ten English songs（說明過去學過,現(xiàn)在是否記得,不是本句的內(nèi)容）I have learnt ten English songs.（learn發(fā)生在過去,但強調(diào)我現(xiàn)在懂英語歌曲）I cleaned the blackboard half an hour ago.（只說明“擦”和其發(fā)生的時間）I have cleaned the blackboa

19、rd.（說明現(xiàn)在黑板是干凈的）The teacher has written some new words on the blackboard（黑板上現(xiàn)在有單詞）The teacher wrote some new words on the blackboard（黑板上現(xiàn)在沒有單詞）（2）一般過去時可以和表示過去的時間狀語連用,如:yesterday, last year, three days ago, just now, 等。現(xiàn)在完成時不能和表示過去的時間狀語連用,其時間狀語可以是since, for, just, ever, never, before, already, yet , s

20、o far, all ones life等（九）規(guī)則動詞的過去分詞和它的過去式相同，即在原形后加ed（d）。已學近80個不規(guī)則動詞的過去分詞約有半數(shù)也和它的過去式相同，現(xiàn)分類如下，以利于同學們記憶：1）原形中的元音字母有變化：get-got-got, sit sat-sat win-won-won spit- spat- spat shine shone- shonefind- found- found hold-held-held meet- met-met stand- stood-stood understand-understood-understood feed- fed-fed h

21、ang-hung-hung2）原形中的輔音字母有變化：make-made-made spill-spilt-spilt have/ has-had-had build-built-builtsend-sent-sent lend- lent- lent spend-spent-spent 3）在原形后加t或d：spoil-spoilt-spoilt learn-learnt-learnt mean-meant-meant hear-heard-heardpay-paid-paid say-said-said lose-lost-lost lay-laid-laid 4）原形中的元音字母和輔音字

22、母都有變化：feel-felt-felt smell-smelt-smelt spell-spelt spelt keep-kept-keptsleep-slept-slept sweep-swept-swept leave-left-left sell-sold-sold tell-told-told catch-caught-caught teach-taught-taught buy-bought-boughtbring-brought-brought think-thought-thought wear-wore-worn5）與原形相同：hit-hit-hit hurt-hurt-hu

23、rt let-let-let put-put-put read-read-readset-set-set shut-shut shut cost-cost-cost cut-cut-cut還有些不規(guī)則動詞的過去分詞與過去式不相同,為便于記憶,也分類如下:1）原形中的元音字母有變化：ring-rang-rung sing-sang-sung drink-drank-drunk swim-swam-swumbegin-began-begun sink-sank-sunk2）在原形上加en：eat-ate-eaten fall-fell-fallen ride-rode-ridden write-w

24、rote- writtenbe-was/were-been rise-rose-risen forget-forgot-forgotten3：在原形上加n：see-saw-seen give-gave-given drive-drove-driven take-took-takenmistake-mistook-mistaken draw-drew-drawn blow-blew-blown grow-grew-grown know-knew-known show-showed-shown throw-threw-thrown4）在過去式上加n：steal-stole-stolen break

25、-brokebroken choose-chose-chosen speak-spoke-spoken wake-woke-woken 5）與原形相同：come-came-come run-ran-run become-became-become6）原形、過去式和過去分詞都不相同的：do-did-done go-went-gone fly-flew-flown lie-lay-lain7）個別動詞有兩個過去式和過去分詞，一個為規(guī)則變化，另一個為不規(guī)則變化：【典型例題】1. I have already _ the magazine for 2 weeks. I must return it t

26、o the library today.A. lent B. bought C. borrowed D. kept解析：答案選D。這是一句現(xiàn)在完成時的句子，表示從過去開始持續(xù)到現(xiàn)在的行為，for 表示一段時間，后接時間長度，本句的意思應(yīng)為：這本雜志我已經(jīng)借了兩個星期了。在這樣的時間狀語為“for+時間長度”的句子里，謂語動詞要有可持續(xù)性，而不能為短暫性動詞，因此，本題只能選D。因為“l(fā)ent”，“bought”，“borrowed”均為短暫性動詞，且“bought”，“l(fā)ent”與句義不符。故選D。下面列出一些短暫性動詞的持續(xù)性表達：arrivebe in borrowkeep buyhave

27、 fall illbe illjoinbe in leavebe away from beginbe on diebe dead等等2. Where are the children? They _ to Beijing.A. have been B. have gone C. have left D. have arrived解析：答案選B。本題首先可排除C，D選項?！半x開此地去北京”為“l(fā)eave for Beijing”，“到達北京”為“arrive in Beijing”. 然后再看A，B 選項，“have been to”意思是“去過某地”，表示曾經(jīng)去過某地，現(xiàn)在已經(jīng)回來或到其他地方

28、，目前人已不在那里?！癶ave gone to”意思是“去了某地”，表示人正去那里或已在去那里的途中。本題中，孩子們不在說話人所在的地方，所以應(yīng)該選擇B，表示他們已經(jīng)去了北京或在去北京的途中。故選B。3. _ has he taught English in this school? For 2 years.A. How long B. When C. How soon D. How often解析：答案選A?！癏ow long”問的是“一段時間”，這句話的意思是，他在這所學校教英語多久了，回答為“兩年了?！薄癏ow long”可與現(xiàn)在完成時一起用。“When”問的是一個時間點，可以和將來時、

29、過去時連用，有時也可以和進行時放在一起用，但“When”不能和完成時一起使用。“How soon”意思是“多久以后”，用在將來時前面，而“How often”問的是一個頻率，可解釋為“多久一次”，回答多為“Once a week.”“Twice a month”等等。故選A。4. Do you still write to your friends these days?No. But I used _ that when I was at school.A. do B. did C. to doing D. to do解析：答案選D。本題涉及到“used”的幾個不同用法，“be used t

30、o doing sth.”表示“習慣于做某事”，“used to do sth.”表示“過去常常做某事”，而“be used to do sth.”則表示“被用來做某事”，主語多為“sth.”.本題“used”前面沒有be動詞，再加上說的是過去我在學校里的事情，所以采用“used to do sth.”這個詞組，整句話的意思就是，當我在學校里的時候，我常常那么做。故選D。5. She was very _ at the _ news.A. surprised; surprising B. surprised; surprisedC. surprising; surprised D. surpr

31、ising; surprising解析：答案選?！癰e surprised at sth.”表示“對感到驚奇”，主語是“somebody”，“surprising”表示“令人驚奇的”，主語多為 “something”, 句子的意思是，她對“這個令人驚奇的消息感到很驚奇”。與此相類似的詞語還有一些，如“exciting令人激動的”，“excited感到激動”，又如“interesting 有趣的”，“interested 感興趣的”等等。故選A。6. He has never _ a pen before.A. lose B. to lose C. lost D. losing解析：答案為C。 本題主要考查現(xiàn)在完成時態(tài)對謂語動詞的要求?，F(xiàn)在完成時態(tài)謂語動詞的結(jié)構(gòu)是have (has)+ 過去分詞。本題空白處需要填過去分詞，這樣的話，那A、B、D就都不對了。7. 誤：The twins have not got home already.正：The twins hav