成都少年时教育 劝君莫惜金缕衣 劝君惜取少年时周末重难点 现在完成时的讲解和练习题一、 构成：主语 + have/has + 过去分词+其他否定式:主语 + havent/hasnt + 过去分词 + 其他。疑问式: Have /Has + 主语 + 过去分词 + 其他?简略答语: (肯定)Yes, 主语 + have/has. (否定)No, 主语 + havent/hasnt.(否定)二、 用法：现在完成时既涉及过去，又联系现在（一）表示过去发生或已经完成的动作对现在造成的影响或结果,也可表示过去已经开始,一直延续到现在的动作或状态常与just（刚刚），already（已经），never（从来没有），ever（曾经），before（以前），yet（仍然，还），once（一次），twice（两次），many times（很多次），how many times（多少次），so far（迄今为止），up to now ,till now 等时间状语连用。如：副词的位置：just常用于肯定句中，放在have / has后，He has just come .never表示否定,放在have / has后, He has never visited the Great Wall.ever用于疑问句中,句型为: Have / Has主语ever 过去分词？“曾经过吗？”用于询问某人过去的经历。 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 finished it.so far用于句首或句末. So far, we have visited the moon.（二）：表示过去已经开始，一直延续到现在的动作或状态。时间状语有：for表示一段时间的词语 I have taught English for 19 years。since表示过去时间点的词语 He has been at this schoolsince 1986.since表示过去的时间状语从句 I have lived here since I was born.since一段时间ago. I have known him since 20 years ago.三、现在完成时态中可以和表示一段时间状语（for，since，how long, all ones life）连用的动词必须用延续性动词（肯定句）。如：be，have，know，live，work，study，learn，teach，keep，speak，talk，draw，wait，wear，walk，sleep，drive，write，do，clean等。Eg. I have been a teacher for nearly 20 years. How long has he lived here?常见终止性动词和延续性动词的相应转换形式如下:1、borrow / lendkeep, 2、buyhave, 3、finish / endbe over, 4、begin / startbe on 5、openbe open 6、 closebe closed, 7、diebe dead8、arrive /come / go / move / reach /get tobe in /at / be here /be there,9、leavebe away（from） 10、go to schoolbe in school / be a student, 11、get upbe up, 12、fall asleepbe asleep 13、fall illbe ill 14、get to knowknow, 15、losebe lost 16、becomebe 17、begin to studystudy,18、return / come back / get backbe back 19、joinbe in / be amember,20、join the armybe in the army /be a soldier 21、receive / get a letterhave a letter 22、 catch / get a coldhave a coldEg. 他参军已有三年.He has joined the army for three years.（错）改为:He has been in the army for three years / since three years ago.Hehas been a soldier for three years / since three years ago.四、现在完成时中应注意的几个问题1. have been to和have gone to的区have been to强调“曾经去过”，现已不在那里，已经回来了have gone to主要强调的是“去了”，可能在去的途中，或在去的目的地。2. have been to和have been in的区别have been to强调人“已回到原地”，后面可接表示“次数”的状语。have been in表示某人“已在某地停留一段时间，现仍在那里”，其后常带表示一段时间的状语练习题I. Fill in the blanks with the proper form.1. I_ already _ (see) the film. I _ (see) it last week.2. _ he _ (finish) his work today? Not yet.3. My father _ just _ (come) back from work. He is tired now.4. Wheres Li Ming ? He _ (go) to the teachers office.5. I _ (work) here since I _ (move) here in 1999.6. So far I _(make) quite a few friends here.7. How long _ the Wangs _(stay) here ? For two weeks.8. I _ just _ (finish) my homework. 9. He _ (go) to school on foot every day. 10._ you _ (find) your science book yet? 11. If it _ (be) fine tomorrow, Ill go with you. 12. The students _ (read) English when the teacher came in. 13. Look! The monkey _ (climb) the tree. 14. My mother _ (come) to see me next Sunday. 15. Ive lost my pen. _ you _ (see) it anywhere? II. Choose the best answer. ( )1、Both his parents look sad. Maybe they _whats happened to him . . knew . have known . must know .will know ( )2、He has _ been to Shanghai , has he ? . already .never .ever . still ( )3、Have you met Mr Li _？ . just . ago .before . a moment ago ( )4、The famous writer _ one new book in the past two year . . is writing .was writing .wrote .has written ( )5、Our country _ a lot so far . Yes . I hope it will be even _ . . has changed ; well . changed ; good . has changed ; better . changed ; better ( )6、Zhao Lan _already _in this school for two years . . was ; studying . will ; study . has ; studied . are ; studying ( )7、We _ Xiao Li since she was a little girl . . know . had known . have known . knew ( )8、Harry Potter is a very nice film .I_ it twice . . will see . have seen . saw .see ( )9、These farmers have been to the United States . Really ? When _ there ? . will they go . did they go