现在完成时讲解一、 基本结构：1、肯定句：主语+have/has+过去分词(done)+------.2、否定句：主语+have/has+not+过去分词+------.3、一般疑问句：Have/Has+主语+过去分词+------.回答: Yes, 主语 + have/has.(肯定) No, 主语 + haven't/hasn't.(否定)二、用法（1）现在完成时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 I have spent all of my money. (含义是:现在我没有钱花了.) Lily has (just/already) come. (含义：Lily现在在这儿)My father has gone to work.(含义是:我爸爸现在不在这儿) （2）现在完成时可以用来表示发生在过去某一时刻的, 持续到现在的动作或状态，常与for（+时间段）,since（+时间点或过去时的句子）连用. ①for+时段 ②since+过去时间（译为：自从……以来） ③since+从句（过去时） ④It is+时段+since+从句（过去时） Mary has been ill for three days. I have lived here since 1998.三、has gone (to), has been (to), has been (in) 的区别1、Have/Has gone(to) :去了(现在不在说话现场)Where is your father？He has gone to Shanghai.2、Have/Has been (to) :去过（已不在去过的地方）My father has been to Shanghai.3、Have/has been in：呆了多久（还在所呆的地方）My father has been in Shanghai for two months. /since two months ago.四、现在完成时的标志 1、现在完成时的含义之一是过去完成的动作对现在仍有影响,用以下四大标志词可以表达这种含义:（1） 以already, just和yet为标志 He has already got her help. 他已得到她的帮助。
He has just seen the film. 他刚刚看过这场电影He hasn't come back yet. 他还没有回来2） 以ever和never为标志 This is the best film I have ever seen. 这是我曾经看过的最好的一部电影He has never been to Beijing. 他从没有到过北京3）以动作发生的次数为标志 He says he has been to the USA three times. 他说他已经去过美国三次了4） 以so far（到目前为止）为标志+before He has got to Beijing so far. 到目前为止他已到了北京She has passed the exam so far. 到目前为止她已经通过了考试2.过去已经开始的动作一直延续到现在, 甚至有可能继续延续下去,我们可以从动作“延续”的特性和“时间”点段的区分入手,进一步学习现在完成时 ①for+时段 ②since+过去一个时间点（过去 从句）为标志 注意： 1)现在完成时不能单独与过去的时间状语连用, 如yesterday, last week, three years ago 等;五、过去分词（一） 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 ” work---worked---worked ,visit---visited---visited(2) 以“ e ”结尾的动词，只在词尾加“ d ” live---lived---lived ,(3) 以“辅音字母 + y ”结尾的动词，将 "y" 变为 "i" ，再加“ ed ” study---studied---studied ,cry---cried---cried(4) 重读闭音节结尾，末尾只有一个辅音字母，先双写该辅音字母，再加“ ed ” stop---stopped---stopped , drop---dropped--dropped（二）不规则动词：1、 AAA型 原型 过去式 过去分词burst burst burst cast cast cast cost cost cost cut cut cut hit hit hit hurt hurt hurt let let let put put put set set set shut shut shut spread spread spreadread read read read原形发音为/ri:d/,过去式和过去分词发音为/red/2、AAB型beat beat beaten3、ABA型become became become run ran run come came come特殊情况4、ABB型bring brought brought buy bought bought build built built burn burnt burntcatch caught caught dig dug dug feel felt felt fight fought fought find found foundhear heard heard hold held heldkeep kept kept lay laid laid lead led led lose lost lostmake made made meet met metsell sold sold shoot shot shot sit sat sat stand stood stood sweep swept swept teach taught taught tell told told think thought thought win won won5、ABC型 begin began begun blow blew blown break broke brokenchoose chose chosen draw drew drawn drive drove driven drink drank drunk fly flew flown forgive forgave forgiven forget forgot forgotten freeze froze frozengive gave given grow grew grownknow knew known ride rode ridden rise rose risen ring rang rungshake shook shaken sing sang sung sink sank sunk swim swam swumswim swam swum throw threw thrown write wrote written六、 瞬间动词（buy, die, join, come，go ,leave, join ……）不能直接与for /since 连用。
要改变动词begin-----be on borrow -----keep buy----have close -----be closed come/arrive/reach/get to-----be in die----be deadfinish----be overgo out----be out leave ----be awayopen----be open ★1、have代替buy My brother has had(不能用has bought) this bike for almost four years.★2、用keep或have代替borrow I have kept(不能用have borrowed) the book for quite a few days.★3、用be替代becomeHow long has your sister been a teacher?★4、用have a cold代替catch a cold Tom has had a cold since the day before yesterday.★5、用wear代替put on b)用“be＋形容词”代终止性动词 1、be＋married代marry 2、be＋ill代fall (get) ill 3、be＋dead代die 4、be＋asleep代fall (get) asleep 5、be＋awake代wake/wake up 6、be＋gone代lose,die,sell,leave 7、be＋open代open 8、be closed代close/shut 9、be＋missing(gone,lost)代lose c)用“be＋副词”代终止性动词 1“be＋on”代start, begin 2“be＋up”代get up 3“be＋back(to)”代return to, come back to, go back to 4“be here (there)”代come(arrive, reach, get) here或go (arrive, reach, get) there等等 d)用“be＋介词短语”代终止性动词 1.“be in/at +地点”代替go to /come to 2.用be in the army 代替join the army 3.“be in/at +地点”代替move to 常用瞬间动词变延续性动词表： 1. have arrived at/in sw. got to/reached sw. come/gone/moved to sw. →have been in sw./at…相应的介词 2. have come/gone back/returned → have been back 3. have come/gone out →have been out 4. have become → have been 5. have closed / opened→ have been clo。