2019年中考语法专题：现在完成时一、语法和句型【知识梳理】 Present perfect tense (现在完成时)项目内容备注概念表示一个过去发生的动作对现在产生的结果和影响。Eddie has eatenmy food.(Eddie ate the food and now Hobo has nothing to eat.)表示一个从过去某个时间开始，延续到现在，并有可能继续延续下去的动作或状态。Eddie has lived with Mille since he was born.Eddiehas livedwith Mille for four years.构成助动词has/have +动词的过去分词动词过去分词规则变化跟对应的过去式一样，在后面加ed.特殊变化详见书本。（P122-123）肯定形式Theyhave finishedtheir homework.He has finishedhis homework.缩略形式：they have=theyve;he has=hes否定形式Theyhavent finishedtheir homework.Hehasnt finishedhis homework.疑问形式Havethey finished their homework?Yes, they have. / No, they havent.关键词already(用于肯定句), yet(用于否定句和疑问句), since+一点时间, for+一段时间,never, ever, three times(其它表示频率的词, once, twice等)before, recently, in the past/last few years, so far, this month, today, now表示过去某一个动作的结果，现在情况依然存在。这时一般不用时间状语。I have lost my pen.包括现在时间在内的时间状语如today, this month, this week等有时也用现在完成时。2.already与yet用法区别 already用于肯定句，一般放在助动词与过去分词之间。yet用于否定句和疑问句，一般至于句末。【典例分析】：I have already worked out this math problem? (改为否定句) I worked out the math problem .解析：already与yet的转换.Key ：have not; yet(1) since的用法since 后面加点时间，如since nearly three years ago或since2008.since引导时间状语从句时，后面的时间状语从句动词用一般过去时.(2)for的用法：for后加一段时间。since/for 可以通过ago进行同义句转换。【典例分析】：1.They have worked in the factory since ten months ago.= They have worked in the factoryfor ten years2.We have learned English fornearly three years.=We have learned English since three years ago.3.I have had a cold _ last Saturday, I have had a cold _ 5 days. I have had a cold _ 5 days ago.所以：_ 5 days= _ 5 days agoKey ：since，for, since, for, since典例分析】：例1.( )I havent seen you _ last Friday.A. for B. since C. from D. on解析：后面的last Friday 是具体时间点，所以应该用since,选B这里需要提醒学生虽然此题后面的last是一般过去时的时间标志，但是跟since连用之后要用现在完成时。Key ：B例2.( )Mr. White came to our school in 2008, and since then he _ us English. (2011盐城)A. teaches B. taught C. has taught D. will teach解析：该题考查的是现在完成时标志性词since，since then自那以后，缩略形式的时间状语从句，后面是主句，主句用现在完成时.Key ：C RegularverbsIrregularverbsBaseformPastparticipleBaseformPastparticiplevisitvisitedhithitrepairrepairedputputlivelivedmeetmetmovemovedmakemadetrytriedsellsoldstudystudiedgivegivenfitfittedwritewritten规则动词的过去分词的构成1.大多数的动词的过去分词是规则的，只需在动词后加-ed；例如：workworked listenlistened jumpjumped visitvisited2.在以-e结尾的动词后只加-d；例如：closeclosed likeliked agreeagreed movemoved3.在以辅音字母加y结尾的动词，应将y改为i再加ed；例如：studystudied carrycarried trytried worryworried4.以重读闭音节结尾的动词，要双写末尾的辅音字母再加-ed；例如： stopstopped dropdropped不规则动词的过去分词的构成1. 有些动词的原形和过去分词相同；例如：putput hurthurtbecomebecome runrun2.改变单词中间元音字母；例如：sitsat winwonholdheld3.把单词结尾的字母d改为t；例如：lendlent spendspent sendsent4.以eep结尾的动词，把eep改为ept；例如：keepkept sleepslept5. 过去分词以aught或ought结尾；例如：teachtaught buybought6.以ay结尾的动词，把ay变成aid；例如：saysaid paypaid7.在原形词尾加n或en；例如：givegiven eateaten还有些动词的过去分词是不规则的，需要特殊记忆【例题精讲】1.- China develops so fast. - Thats true. It_ a lot already.A.changesB.changedC.will change D.has changed答案D2.- How do you like your English teacher? - He is great. We_ friends since three years ago.A.were B.have madeC.have been D.have become答案C3.I hear the tall girl wearing glasses is your new classmate. Shes from America, _?A.has she B.isnt she C.hasnt she D.does she答案B4.- Is the film interesting? - I thought it would be. But_, its very boring.A.in all B.in factC.in addition D.in future答案B5.- Why dont you go to the movie with me, Betty? - Because I_it before.A.saw B.have seenC.see D.had seen答案B6.Holly has_ fed the dog, but she hasnt watered the plants _.A.still; already B.already; yetC.yet; still D.yet; already答案B7.- Have you ever been to Nanning? - Yes, _. A.I was B.I doC.I am D.I have答案D8.The trip to Hong Kong was_and we felt_.A.pleased; pleased B.pleased; pleasantC.pleasant; pleased D.pleasure; pleasant答案C9.Susan and I have been friends_ five years.A.since B.afterC.for D.over答案C10. Oh, Mrs. King, your necklace looks nice. Is it new? No, I _ it for two years. A.had B.have hadC.boughtD.have bought答案B11.I dont want to see the