现在完成时用法小结
一、现在完成时的构成
动词have(has)+ 过去分词
否定式have(has) not+ 过去分词
文明祭扫疑问式:have\has蓄势待发 not+主语+过去分词;have\has +主+not+过去分词
二、现在完成时态的用法
1、表示开始于体寒的症状过去动作一直持续到现在,而且还可能继续持续下去。这时,谓语动词一般为延续性动词
例如:I have been a teacher for 5 years\since 5 years ago.(五年前是个时间点。一直持续到现在的的状态,一直在做老师,以后还是老师。)
      They have lived here for 7 years.(第一层含义,到说话这一刻,一直住在这里,这是
一个持续状态。第二层含义,如果他们正在搬家时候说这句话,则说明live这一事实不再持续,到此为止,他们可能要搬去别处住。)
这一用法的特点:谓语动词为延续性动词;动作发生在过去,持续到现在,并有可能继续下去;和“一段时间”的状语连用。
since+时间段:I have worked in this place since 1990.
                I have lived in Xian since I left school\since 5 years ago
for+ 时间点:  I have worked in this place for 20 years.
                I have lived in Xian for 5 years ago.
到目前为止…”:until now, ,up to\ till\until now,so far
              Until now,I have been a monitor for 3 years.(放在句末亦可)
              Our country has until now, ,up to\ till\until now,so far
Won 20 golden medals.
“在最近几个世纪、年、月以来……”in \over \during the past few years,for the last few century,through centuries,throughout the past decades.
For the last few decades, great changes have taken place in Beijing.
2.表示过去某时发生或完成的某一动作,谓语动词是短暂性动词(对现在造成的影响或结果)
(这一用法对中国学生来说是比较难理解的一种,因为它使用的是短暂性动词和一般过去时态有着比较容易混淆的关系。)
例如:
(1)I have just cleaned my clothes. 我刚洗过衣服。
(“洗衣服”是发生在过去的动作,对现在造成的结果是“衣服干净了”)       
(2)He has broken his leg.他的腿跌断了。(言外之意:现在也许在医院,可能不能参加郊游或者集体活动什么的了)
He broke his leg.他过去摔伤过腿。(单纯表示跌断过腿。一种过去的经历,现在腿是好的。)
注意,现在完成时态不能与明确指出时间的状语连用,比如yesterday,last year,3 days ago.但是可以与不明确表示时间的状语连用。与现在完成时连用的时间状语有:
already已经  用于肯定句的中间和末尾处)He has already arrived.
often(常常,经常)I have often thought that I were a bird.
never  (从不  “从未发生过”用于中间处)I have never seen such a good movie.
ever 曾经  用于疑问句和肯定句的中间处)She has ever done this.
just    (刚刚  用于中间处)
--Would you like something to eat?
--No,thanks.I have just had dinner.
yet    (已经  用于疑问句的句末 /   用于否定句的句末)
Has he arrived yet?No,he hasnt.
I have not returned the book yet..
由于这一用法中的谓语动词通常是短暂动词(即动作在短时间或者瞬间终止不再延续),所以不能和“since\for+一段时间”连用. 这些短暂性动词有:come go leave kill die lose buy give marry join bring heard
错例:Mary has bought a new backpack since yesterday.(从昨天起一直在买书包?)X
I have bought this backpack for a day.(买书包不可能买了一天,难道一直在讨价还价,废寝忘食的讨价还价么?)X
正例:Mary has bought a new backpack.(现在用的是新书包)
      Mary bought a new backpack yesterday.(昨天买的新书包,买这一动作于昨天发生并结束,没有强调是否现在用着新书包这一感情彩,只陈述了昨天买书包这一事实)。
错例:I have left my home for 3days.(离开这一动作发生了三天吗?)
正例:I left my home 3 days ago.(我三天前离开家的。离开这一动作三天前发生并结束了。)
      I have been away home for 3 days..三天没在家了。
但是,短暂性动词的否定式可以用完成时,表示一种尚未发生的持续的状态
比如:I haven’t seen a beautiful girl for a long time.
      She hasn’t bought a pair of shoes since last year.
      He hasn’t heard from his son since 2005.
三、现在完成时与一般过去时的用法比较
现在完成时表示过去的动作一直延续到现在甚至会继续下去或表示过去的动作对现在造成的影响;一般过去时表示动作发生的时间在过去并且有可能结束在过去。试比较:
例如:He lived in Beijing for 2 years and then moved to Shanghai(曾在北京住过两年,后来搬去上海了)
He has lived in Beijing for 2 years.(在北京住了2年了,还可能住下去或者不住下去,不得而知。除非你看到他正在搬家。)
My dad smoked for 2 years.(我爸爸抽过两年烟,现在戒了。抽烟的习惯这一事件动作发生在过去结束在过去)
My dad has smoked for 2 years.(我爸爸已经有两年的抽烟史了,现在仍然保佑抽烟这一习惯。)
I have taught here for fifteen years. 我在这儿已经教了十五年。(表示十五年前的动作一直延续到现在,还可能会继续。)
I taught here for a year. 我过去在这儿教过一年。(表示“我“现在已经不在这儿任教了)
再利用一个对话对现在完成时态和一般过去时的区别进行一番感受:
--Have you seen the movie FINDING NEMO?(询问对这一电影是否看过?强调的是对电影内容是否了解)
龙的传人歌谱--Yes,I have.(已看过,知道内容是什么)
魔力云学术
--When did you see it?(看电影的具体时间)
--I saw it last Sunday.(给出具体看电视的时间点 是上周天)
--Did you see it alone?
--No,I saw it with my parents.(看的时间是一般过去时 昨天看的 并且看这一动作已经结束在昨天)
练习:
I.翻译下列句子:
你曾经吃过鱼和薯条吗?
我刚刚丢了我的化学书。
我以前从来没去过那个农场。
他已经吃过午饭了。
你已经看过这部电影了吗?
我哥哥还没回来。
我上星期看过这部电影。
在1992年他住在这里。
II. 用过去时或现在完成时填空:
1. _________ you __________ (have) lunch ?    Yes.
  When ________ you __________ (have) it?  I ____________ (have) it at 12:00.
2. _________ you __________ (write) a letter to your aunt yet?
  Yes, I ___________.  I ________________ (write) one last week.
3. _________ he ___________ (finish) his homework?    Not yet.
4. _________ they ever __________ (be) abroad?    Yes, just once.
谭嗣同名言5. Your father _________ just ___________ (finish) his work.
6. Your father _________ (finish) his work just now.
7. Last term I __________ (learn) many English words.
8. They ____________ (not read) the interesting books yet.