新目标八年级英语(下)Unit9现在完成时.ppt

现在完成时态是中考的必考时态，由于现在完成时态既涉及到过去，又联系到现在，和一般过去时态，一般现在时态，现在进行时态既有联系，又有区别，所以同学们掌握起来比较困难。,现在完成时怎么用呢？请看动画：,1.现在完成时表示过去发生或已经完成的某一动作对现在造成的影响或结果。(汉语中常用“已经”、“过”、“了”等表达）通常与表示包括现在在内的时间副词 just，already,before,yet,never,ever 等状语连用。例如：I have never heard of that before.Have you ever ridden a horse?She has already finished the work.Have you milked the cow yet?Yes,I have done that already.Ive just lost my math book.,现在完成时的构成,助动词have(has)+动词的过去分词注：has 用于第三人称单数，have 用于其他所有人称。规则动词的过去分词变化与过去式相同，不规则变化则须单独记忆。,用法：,2.现在完成时表示过去已经开始，持续到现在,也许还会持续下去的动作或状态。可以和表示延续的时间状语连用。如for、since 等引导的时间状语。（注意：句中谓语动词要用延续性动词）,一段时间的表达方法有两种:for:+一段时间 for a year for two weeks for three years,过去的某一时刻,since nine since last week 一般过去时态的时间状语从句 since you came since you got home.,注意:for 和since 所引导的时间状语都表示一段时间.,He has been away since last week.,He has been away for one week.,对划线部分提问都用How long,Since,（3）have been(to)和have gone(to)的区别：have/has been(to)表示“曾经到过某地”，说话时此人不在那里，已经回来。侧重指经历。have/has gone(to)表示某人“已经去某地了”，说话时此人可能在路上或已到那里，反正不在这里。试比较：He has been to Beijing.他曾去过北京。（人已回来，可能在这儿）He has gone to Beijing.他已经去北京了。（人已走，不在这儿）。,现在完成时与一般过去时有何区别呢？请看：,一般过去时与现在完成时之比较,1）一般过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作，和现在不发生关系。而现在完成时表示过去发生的某一动作对现在造成的影响或结果，强调的是现在的情况。2）一般过去时常与具体的时间状语连用，而现在完成时通常与模糊的时间状语连用，或无时间状语。一般过去时的时间状语有：yesterday,last week，ago,in1980,in October,just now,等具体的时间状语。共同的时间状语有：this morning,tonight,this summer,before,already,等。现在完成时的时间状语有：for,since,ever,never,just,already,yet,in past years等不确定的时间状语。,请大家认真分析比较下列各例句：,I saw this film yesterday.（只说明动作发生在过去。）I have seen this film.（强调对现在的影响，电影的内容已经知道了。）She has returned from Paris.（她已从巴黎回来了。）She returned yesterday.（她是昨天回来的。）He has been in the League for three years.(在团内的状态可延续)He joined the League three years ago.(三年前入团，joined为短暂行为。)注意：句子中如有一般过去时的时间副词（如 yesterday,last week,in 1960）时，不能使用现在完成时，要用过去时。例如：（错）Tom has written a letter to his parents last night.（对）Tom wrote a letter to his parents last night.,现在完成时与瞬间动词,瞬间动词可以用于现在完成时，但不能和表示一段时间的状语连用。如可说“He has left.”但不能说“He has left for three years.”如果要表达“他已走了三年了”可用以下几种表达法：,一、用ago,使用一般过去时。He left here three years ago.,二、用“It is+一段时间since 一般过去时从句”It is three years since he left here.,三、用“一段时间have/has passed+since+一般过去时从句”,Three years have passed since he left here.,以上三种表示方法适用于所有瞬间动词。,另外，还可用其它表示方法，但只适用于部分瞬间动词。具体办法是将瞬间动词转化为表延续的动词或者表状态的be+名词形容词或副词介词短语等。,1.直接转化成延续性动词 buy catch(get)a cold borrow come/go/become,have,have a cold,keep,be,2.转换成be+名词 join the army join the Party go to school,be a soldier,be a Party member,be a student,3转换成be+形容词或副词 die finish begin leave fall sleep close open,be dead,be over,be on,be away,be asleep,be closed,be open,4.转换成 be+介词短语 go to school join the army,.我们买这本书三年了.,We have had the book for three years.,他感冒三天了.,He has had a cold for three days.,We bought the book three years ago.,He caught a cold three days ago.,一般过去时态和现在完成时态可以构成同义句,be in school,be in the army,自从上星期以来,我就借了这本书.,I have kept the book since last week.,我成为一个学生两年多了.,I have been a student for over two years.,I borrowed the book last week.,I became a student two years ago.,Mr Black死了三年了。,Mr Black has been dead for three years.,Mr Black died three years ago.,小明参军半年了。,Xiao Ming has been a soldier for half a year.,Xiao Ming joined the army half a year ago.,我们上了8年学了。,We have been students for eight years.,下课10分钟了,The class has been over for ten minutes.,9.电影开始了一小时了,The film has been on for an hour.,现在完成时“三看三用”,一看时间状语。如果句中没有表示过去确切时间的状语，常用现在完成时；如果有，则只能用一般过去时。如：I have visited the factory.I visited the factory last year.,二看句首有无疑问词。如果笼统地问人家做过某事了吗（句首无疑问词），常用现在完成时；但进一步询问何时、何地、何原因、用什么方式做那事时（句首有疑问词）就要用一般过去时。如：,Have you had your breakfast?Yes,I have.When did you have it?At seven thirty.,三看句中谓语动词是否为延续性动词。如果表示的动作或状态一直延续到现在，最好选用延续性动词，并使用现在完成时；如果是瞬间动词，则用一般过去时。如：He has been a league member for two months.He joined the Youth League two months ago.,注意：这种用法是以连贯性问答为背景的。否则就需要具体情况具体分析。如：How many words have you learned by heart?How did you learn them by heart?,Exercises,()1.Youve never seen such a wonderful film before,_?A.havent you B.have you C.do you D.dont you()2.I have watched the game.When _ you _ it?A.have;watched B.do;watch C.did;watch D.will;watch,()3.Mr.Green _ in China since five years ago.A.lived B.has lived C.lives D.is going to live()4.His grandma _ for two years.A.died B.has died C.was dead D.has been dead,B,C,B,D,()5.Where is Han Mei now?She _ to Shanghai.She will be back in two days.A.has gone B.has been C.goes D.had gone()6._ you _to the United Stated?No,never,but I went to Canada a few years agoA.Have;been B.Have;gone C.Did;go D.Do;go,()7.You havent changed your mind,_?A.do you B.are you C.have you D.did you,()8.How long have you _ the football team of the school?A.played B.been at C.joined D been on,A,A,C,D,()9.Where have you _ these days?I have _ to Kunming with my friends.A been,gone B been,been C gone,been D gone,gone()10.How long have you _ this book?A.bought B.borrowed C.had D.lent()11.Excuse me,_ you seen the film yet?Yes,I _ it last night.A have,see B have,have seen C have,seen D have,saw()12.He has never ridden a horse before,_?A.is he B.isnt he C.hasnt he D.has he,B,C,D,D,Thank you,everyone!Good-bye!,