---------------------------------------------------------------最新资料推荐------------------------------------------------------现在完成时精讲精练现在完成时现在完成时的构成现在完成时的主要用法现在完成时的时间状语短暂性动词与时间段的关系 have been 与have gone 比较与一般过去时的用法比较上一页主菜单下一页1/ 40现在完成时的构成have (has）+ 过去分词上一页主菜单下一页---------------------------------------------------------------最新资料推荐------------------------------------------------------ 现在完成时 ( present perfect tense)pastpresent(now)futuredo my homework3/ 40现在完成时的主要用法1.表示过去发生的某一动作对现在造成的影响或结果。
-- It’s so dark. --Someone has turned off the light. (有人刚把灯关了,对现在造成的结果是:现在很黑) -- Are you free? --I have finished my homework. I am free (我已经完成了家庭作业,对现在造成的结果是很有空)上一页主菜单下一页---------------------------------------------------------------最新资料推荐------------------------------------------------------ 现在完成时的主要用法2.表示过去某一时间开始并一直持续到现在的动作或状态，常和表示一段时间的时间状语连用，谓语动词多用延续性动词。
（这一用法与现在完成进行时相同： have / has + been + v.ing。
）They have lived here for 30 years. 他们已经在这儿住了30年。
(30年以前开始住在这儿，现在还住在这儿。
) I have learned English since I was five years old.我从五岁时就学英语。
（五岁时开始学英语，到现在还在学。
）5/ 40现在完成时的运用:? 1）already 和yet ? already用于肯定句，放于句中或句末，在句中时，位于助动词或系动词后，实义动词前。
? yet用于否定句和疑问句，一般在句末。
? I have already finished my homework. ? I haven’t finished my homework yet.---------------------------------------------------------------最新资料推荐------------------------------------------------------ ? 2）ever和never ? ever用于肯定句和疑问句中，在句中位于助动词或系动词后，实义动词前。
? never用于句中，助动词或系动词后，实义动词前，表示否定意义。
? He has ever been to Paris.? He has never been to Paris.7/ 403） just表示“刚刚”（用于完成时态时，与 already，never 等副词的位置一样，多用在助动词 have/has和动词过去分词之间）? He has just come back. 他刚刚回来。
? They have just finished the work. 他们刚刚完成那项工作。
---------------------------------------------------------------最新资料推荐------------------------------------------------------ 4）for 和 since for 后面跟一段时间，since后面跟的是时间点，这个时间点可能是单词、短语或一般过去时的句子。
带有for或since短语的句子，谓语动词要用延续性动词。
He has been here for three days.He has been here since yesterday.He has been here since two days ago / last Monday.He has been here since his wife died.9/ 40现在完成时的主要用法3.表示人曾有过或到目前为止从未有过的经历.I have ever been to the Summer Palace?(我曾去过颐和园)I have never had a car.(我从未有过汽车。
)上一页主菜单下一页---------------------------------------------------------------最新资料推荐------------------------------------------------------ 现在完成时的时间状语◆常与①already, ③ever,②never, ④just,⑤yet,⑥before,⑦up to now,⑧so far,⑨for the last few weeks⑩these days, ⑾since ⑿for a long time 连用上一页主菜单下一页11/ 40现在完成时的主要用法2.表示过去已经开始, 持续到现在的动作或状态.常与since + 过去的时间点，for + 一段时间，so far 等时间状语连用。
I have learnt English for more than ten years.我已经学了10多年的英语。
(从10年前开始,持续到现在还在学)上一页She has swum since half an hour ago. 我已经游泳了半个小时(半个小时前已经开始游泳,到现在还在游)主菜单下一页---------------------------------------------------------------最新资料推荐------------------------------------------------------ 1.for + 一段时间Eg. I have been here for 5 weeks. He’s studied English for 3 years.13/ 402. since +(表示过去某一时间的)时间点单词词组从句(一般过去时)Eg. I have been here since 2000.I have been here since 5 years ago.I have been here since I graduated in 2000.---------------------------------------------------------------最新资料推荐------------------------------------------------------ 注2): 对for或since引导的时间状语提问必须用how long, 决不能用when. Eg. I have lived here for 10 years. How long have you lived here?She has stood here since 2 hour ago.How long has she stood here?15/ 404. 过去分词的构成：规则动词过去分词的构成和过去式一样，不规则动词的过去分词见课本（八下或九年级课本最后一页）。
记忆不规则动词的过去式和过去分词，可以分为以下几类来记：---------------------------------------------------------------最新资料推荐------------------------------------------------------A A A型原形、过去式和过去分词同形：hitput let read costhit hitput put let let read read cost cost17/ 40A B B型过去式和过去分词同形：buy find feel havebought foundfelt hadbought foundfelt had---------------------------------------------------------------最新资料推荐------------------------------------------------------A B C型原形、过去式和过去分词各异do go flywritedid went flewwrotedone gone flownwritten19/ 40A B A型原形与过去分词同形comecamebecome becameA A B型原形与过去式同形beatbeatcome becomebeaten---------------------------------------------------------------最新资料推荐------------------------------------------------------ 延续性动词和非延续性动词（终止性动词）延续性动词表示能够延续的动作如：learn, work, keep, have, wait, stay等。
延续性动词可以与表示时间段的状语连用。
非延续性动词也称终止性动词、瞬间动词，表示不能延续的动作,这种动作发生后立即结束,不能与表示一段时间的状语连用。
如:die, begin, finish, come, go, open, leave, join,marry / get married等。
21/ 40leave--be away (from) join-- be in/be a/an…come/go (to) --be (in/at)start/begin-- be onarrive (at/in)--be (in/at) die-- be deadget (to)-- be (in/at)close--be closedreach-- be (in/at) buy-- haveopen--be open return-- be backborrow-- keep finish-- be overmarry--be married become--be---------------------------------------------------------------最新资料推荐------------------------------------------------------ 短暂性动词与时间段的关系●短暂性动词在肯定句、疑问句中不能与时间段连用，这些动词是：①become,②begin,③buy,④borrow,⑤come (go, arrive),⑥die,⑦finish,⑧join,⑨ leave, 等。