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Unit 10 I’ve had this bike for three years.Section A3 Grammar focus现在完成时一、意义与构成1. 意义：表示过去1) 发生或已经完成的动作对现在造成影响或后果2) 某一时间开始并一直持续到现在的动作或状态2. 基本构成：have/has+ done (过去分词)3. 句型基本结构：主语+have/has+ done (过去分词)a. 肯定句：主语+have/has+ done (过去分词)b. 否定句：主语+have/has+not+ done (过去分词)c. 一般疑问句：Have/Has+主语+ done (过去分词)d. 特殊疑问句：特殊疑问词+have/has+主语+ done过去分词二、过去分词与动词的过去式一样，动词的过去分词有规则动词过去分词和不规则动词过去分词两种。
1. 规则动词：规则动词的过去分词的构成规则与规则动词的过去式的构成规则相同1) 一般动词，在词尾直接加“ ed ”如：work—worked—worked; play—played—played; enjoy—enjoyed—enjoyed.2) 以“e”结尾的动词，只在词尾加“d ”如：dance—danced—danced; live—lived—lived; place—placed—placed.3) 以“辅音字母+ y ”结尾的动词，将“y” 变为“i” ，再加“ed”注意：元音字母+y结尾的动词的过去分词的变法参见一般动词。
如：carry—carried—carried; hurry—hurried—hurried; cry—cried—cried4) 重读闭音节结尾，末尾只有一个辅音字母，先双写这个辅音字母，再加“ed”如：plan—planned—planned; stop—stopped—stopped; drop—dropped—dropped2. 不规则动词不规则动词的过去分词有5种形式：A-A-A 如：cost—cost—cost; cut—cut—cut; hit—hit—hitA-B-B 如：bring—brought—brought; build—built—built; catch—caught—caught;keep—kept—kept; sell—sold—sold; smell—smelt—smelt;learn—learnt—learnt; say—said—said; meet—met—met;make—made—made; leave—left—left此类变化涉及到的动词较多，需要同学们认真记忆。
A-B-C 如：begin—began—begun; blow—blew—blown; drive—drove—drive;break—broke—broken; forget—forgot—forgotten; eat—ate—eaten;take—took—taken; do—did—done此类变化涉及到的动词较多，需要同学们认真记忆。
A-A-B 如：beat—beat—beatenA-B-A 如：come—came—come不规则动词的过去分词变化规则多，但是还是有一定的规律所循，希望同学们多花心思，细心记下，这是使用完成时态的基础。
三、用法1. 现在完成时用来表示过去已发生过或完成的动作或状态，但其结果却和现在有联系，也就是说，动作或状态发生在过去但它的影响现在还存在。
I have spent all of my money. 我花光了身上所有的钱。
(含义是：I don’t have any money now.)Jane has laid the table. Jane已经把桌子摆好了。
(含义是：We can sit and have dinner.)Michael has been ill. Michael病了。
(含义是：He can’t come to school.)He has returned from abroad. 他已经从国外回来了。
(含义是：He’s at home now.)2. 现在完成时可以用来表示发生在过去某一时刻的,持续到现在的情况,常与for（+时间段），since（+时间点）连用。
Mary has been ill for three days. Mary已经病了三天了。
I have lived here since 1998. 我从1998年起一直住在这。
I have been a teacher for 10 years. 我当老师已经10年了。
注意：点动词（buy, die, join, finish等）不能直接与for, since 连用，需要改变动词。
1) have代替buyI have bought new car. 他买了辆新车。
(含义：他自己有车，不用搭别人车等。
)I have had this bike for almost 7 years. 我买这辆自行车七年了。
2) 用keep或have代替borrowHe has kept the book for a long time. 他借这书好长时间了。
3) 用be in替代come to/ join/ move to等How long have you been in America? 你来美国多久了？4) 用be+副词替代start/ get up/ return to/go back toThe show has been on for half an hour. Hurry up!演出已经开始了半个小时了。
快点！I’ve been up for an hour, but I still feel sleepy.我起床已经一个小时了，但是我还是觉得很困。
He has been back to his hometown for a year, but he’s still missing the life in thecity.他回到故乡都一年了，但是他还是很怀念城市生活。
总之，后加时间的完成时表达中，都表达一个动作所延续的时间，而点动词只表达那一动作，动作之后所处的状态，应该用相应的状态词来表达，如come是“来”的意思，而来之后的日子都是“在…”因为不能用come表达，应该用be in…来表达，意为“一直处于…”。
3. 现在完成时的时间状语现在完成时属于现在时范围，故不能和过去的时间状语连用。
如：yesterday, last Sunday,in1990, three years ago等。
但是，在强调动作产生的后果和影响时，可以和一些表示不确定的时间状语连用。
如：I have finished my homework yesterday. (×)I finished my homework yesterday. (√)1)副词already和yetalready一般用于肯定句中，yet一般用于否定句和疑问句中。
如：I’ve already slept for 12 hours but I’m still feeling tired.我都睡了12个小时了可是我还是很累。
I haven’t finished working yet.我还没有完成工作。
Have you found your lost cat yet?你找到你丢了的小猫了吗？2)ever和never多用于否定或疑问句中，表示“曾经”或“从未”。
如：---Have you ever been to the Great Wall? 你曾经去过长城吗？---No, I haven’t. I have never been to the Great Wall. 没有。
我从未去过长城。
3)用表示到说话为止的过去时间状语，如：just, before, up to now, the past few years 等。
如：I have just finished my paper. 我才写完我的论文。
I’ve dream about that before. 我以前梦到过那个情景。
Up to now, he has got 3 gold medals in the Olympic Games.到现在为止，他已经在奥运会中取得了三块金牌。
He has been there three times the last few days.近几年他去过那里三次了。
4)用包括“现在”在内的时间状语，如：now, today, this morning (month, year, term)等。
如：---Have you met him today?---No, I haven't.---今天你见过他吗？---没有。
How many times have you been there this year?今年你去过那里多少次？四、练习（一）单项选择1. Both his parents look sad. Maybe they __________ what happened to him.A. knewB. have knownC. must knowD. will know2. Have you met Mr. Li __________?A. justB. agoC. beforeD. a moment ago3. The famous writer __________ two new books in the past two year.A. is writingB. was writingC. wroteD. has written4. Harry Potter is a very nice film. I __________ it twice.A. will seeB. have seenC. sawD. see5. ---These farmers have been to the United States.---Really? When __________ there?A. will they gB. did they goC. do they goD. have they gone6. ---__________ you __________ your homework yet?---Yes. I __________ it a moment ago.A. Did; do; finishedB. Have; done; finishedC. Have; done; have finishedD. will; do; finish7. His father __________ the Party since 1978.A. joinedB. has joinedC. was inD. has been in8. ---Do you know him well?---Sure. We __________ friends since ten years ago.A. wereB. have beenC. have becomeD. have made9. ---How long have you __________ here?---About two months.A. beenB. goneC. comeD. arrived10. The house is dirty. We __________ it for weeks.A. didn’t cleanB. hadn’t cl eanedC. don’t cleanD. haven’t cleaned11. You don’t need to describe her. I __________ her several times.A. had metB. have metC. metD. meet12. He __________ English for six years by the time he takes his examination.A. has studiedB. studiedC. will studyD. had studied（二）翻译句子1. 我父亲以前到过长城。
