1、现在完成时一、 意义:1. 表示过去发生的动作对现在造成的影响或结果。2. 表示从过去已经开始持续到现在的动作,并有可能一直持续下去。二、 结构:肯定:主语+have/has+动词的过去分词+其他否定:主语+have/has+not+动词的过去分词+其他一般疑问句:Have/has+主语+动词的过去分词+其他?Eg:I have finished my homework.(肯定)I havent finished my homework.(否定)Have you finished your homework?(一般疑问句)Yes,I have. No,I haventHe has seen t
2、he film three times(肯定)He hasnt seen the film three times(否定)Has he seen the film three times?(一般疑问句)Yes,he has. No,he hasntTips:肯定句变否定句,因为有动词have/has,直接在助动词have/has后加not。变一般疑问句,因为有助动词have/has,助动词have/has提前,注意第一人称变第二人称。三、动词原形变动词过去分词规则(1) 一般情况下在动词后直接加ed(2) 以不发音的e结尾的动词直接加d(3) 以辅音字母加y结尾的变y为i加ed(4) 以重读闭
3、音节结尾的辅元辅结构双写尾字母加ed(5) 不规则变化需要特殊记注:动词原形变过去分词和动词原形变过去式规则变化是一样的,不规则的是不一样的四、时间标志词already(已经),just(刚刚),so far(到目前为止),before(以前),in the past+时间段(在过去的.),ever(曾经),never(从不),yet(还,用于否定和疑问句),for+时间段,since+时间点,since+时间段+ago,since+从句(从句用一般过去时) 五、 现在完成时注意点1. have been to,have gone to,have been in 区别(1) have been
4、 to 表示曾经去过某地,常和just,ever,never,次数:once,twice,three times.等连用,表示去过某地几次。Eg:He has been to Hongkong three times.他已经去过香港三次了。I have never been to America.我从没去过美国(2) have gone to,意思是去了某地,表示说话人不在场,一般不用于第一、第二人称作主语。Eg:-Where is Tom?Tom在哪儿?-He has gone to the library.他去图书馆了。(3) have been in 表示在某地待了多长时间,常与表示一段
5、时间的状语连用Eg:John has been in Beijing for three years.John 曾经在北京待过三年2. 短暂性动词不与一段时间连用常见短暂性动词转化成延续性动词begin/go/get/reach/arrive/movebeleavebe awaydiebe deadborrowkeepbuyhavebegin/startbe onfinishbe overwakebe awakeopen/closebe open/closedjoinbe inmarrybe marriedget upbe upfall asleepbe asleepcatch a coldhave a coldEg:The film has begin for 10 minutes.()The film has been on for 10 minutes.()I have bought the book for two days.()I have had the book for two days.()