2020 学年人教版英语八年级下册 Unit 8 Have you read Treasure Island yet？ 一． 基本结构：助动词 have/has+过去分词(done) 二．　句型： 否定句：主语+have/has+not+过去分词+其他. 一般疑问句：Have/Has+主语+过去分词+其他. 简略答语: Yes, 主语 + have/has.(肯定) 　　　　　 No, 主语 + haven't/hasn't.(否定) 三．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 (so far).现在我没有钱花了。　　 Guo zijun has (just/already) come . 郭子君现在在这儿。 My father has gone to work. 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（用行为动词表示）或状态（be 动词表示）常与 for（+时间 段）,since（+时间点或过去时的句子）连用. 　　① for+时段 　　② since+过去一个时间点（译为：自从……以来） 　　③ since+时段+ago 　　④ since+从句（过去时） 　　⑤ It is+时段+since+从句（过去时） 　 　Mary has been ill for three days . 　 　I have lived here since 1998. 　四．　has gone (to), has been (to), has been (in) 的区别 　　 Have/Has gone(to) :去了(现在不在说话现场) Where is your father？He has gone to Shanghai. Have/Has been (to) :去过（已不在去过的地方） My father has been to Shanghai. 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. 五．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: 　* 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。 　* 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。 　* 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。 　* 以 so far（到目前为止）为标+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。 　* ① for+ 时段 ② since+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; 2)不能与 when 连用 2.现在完成时往往同表示不确定的过去时间状语连用 　六．过去分词 　　 　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。四点变化规则： 　　(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 　（5）不规则动词的变化 七． 瞬间动词（buy,die,join,come，go ,leave,join ……）不能直接与 for since 连用。要变成相应的延续性动词 buy----have borrow -----keep come/arrive/reach/get to-----be in go out----be out leave ----be away begin-----be on finish----be over open----be open close -----be closed die----be dead ★ 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 become How 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 　　a)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 b)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 　　c)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 close/open 　　6. have got up → have been up； 　　7. have died → have been dead； 　　8. have left sw. → have been away from sw. 　　9. have fallen asleep/got to sleep → have been asleep ； 　　10. have finished/ended/completed → have been over ； 　　11. havemarried → have been married； 　　12. have started/begun to do sth. → have done sth. ； 　　13. have begun → have been on 　　14. have borrowed/bought →have kept/had 　　15. have lost → haven’t had 　　16. have put on →have worn 　　17. have caught /get a cold → have had a cold； 　　18. have got to know → have known 　　19. have/has gone to → have been in 　　20. have joined/have taken part in the league/the Party/the army →have been a member of/ have been in/have been the Party’s member/the league member/the soldier… 现在完成时练习(一) A)选用 have, has 填空: 1.I _______ told him the news. 2.She ________ come back from school. 3.You ________ won the game. B)按要求改写下列各句: 4.They have bought a computer.(改成否定句) __