Unit9 Human Biology 语法知识点扫盲
完成时态
观察句子
I am Li Fan, Chairman of the Students' Union. I am writing to draw your attention to some improper behaviour on our campus: littering and scribbling. It ①has been making our school dirty and unpleasant. It is clearly not appropriate for a student to litter and scribble about. Last week, the Students' Union held a meeting to ek some solutions to the problems. After the meeting，the headmaster said that the school ②had made efforts to improve this situation and more dustbins would be placed around. Recently, the Students' Union ③has t up specific rules against such behaviour. At the same time, all of us should develop good habits and better behave ourlves. We believe that with the joint efforts, our school will become a more enjoyable place in the near future.
感悟：
1．现在完成时强调动作的完成，如加黑处③；其结构为have/has＋现在分词。
2．现在完成进行时的构成：have/has been＋现在分词。现在完成进行时表示动作开始于过去，并一直
持续到现在，动作可能仍在进行，也可能刚刚结束。如加黑处①。
3．过去完成时用于主从复合句，主从句动作都发生在过去，且有先后关系，如加黑处②。
语法知识精讲
完成时表示一个完成的动作，用来表示现在、过去或者未来某个时间点已经或者将会完成的动作。完成时包括现在完成时、现在完成进行时、过去完成时和过去完成进行时四种时态。
一、现在完成时
1．现在完成时的构成为have/has＋done，表示发生在过去的动作或存在的状态到说话时刚刚完成或结束。现在完成时常与up to now、so far、already、yet、now、recently、in the past few years、just等表示时间的短语连用。
form2．在条件、时间或让步状语从句中，表示将来某时之前已完成的动作。
3．下列情况下常用现在完成时：
①It is/has been＋一段时间＋since从句
②This/That/It is the first/cond/...time that＋现在完成时
③It/This is the best/worst/most interesting/...＋名词＋从句(现在完成时)
◆In the past few years，great changes have taken place in my hometown.
在过去的几年里，我的家乡发生了巨大变化。
◆When you have learned English，you will find it a bridge to so much knowledge.
当你学习英语之后，你会发现它是通往丰富知识的桥梁。
◆It is/has been twenty years since I saw her.
我已经二十年没见她了。
◆This is the first time that we have en a film in the cinema as a family.
这是我们全家第一次在电影院看电影。
◆This is the most interesting novel he has ever written.
干杯的英文
这是他写的最有趣的一部小说。
会计学习软件二、现在完成进行时
1．现在完成进行时的构成为have/has＋been＋doing，表示过去的动作持续到现在并有可能延续下去，常和for、since引导的时间状语连用。
2．表示重复性动作。
3．表示某种感情色彩。
◆The manager has been telling the workers how to improve the program since 9 am.
从上午9点开始，经理就一直在告诉工人如何改善这一方案。
情人节快乐用英语怎么说◆Too much has been happening today.
今天真是一个多事的日子。
注：
现在完成进行时和现在完成时的区别：
(1)现在完成进行时可以表示动作的重复，而现在完成时表示动作发生过。
◆Someone has phoned you.
有人给你打电话了。
◆Someone has been phoning you.
有人一直在给你打电话。
(2)现在完成进行时强调动作，而现在完成时则强调结果。
anything goes◆He has been cleaning the street.
他一直在打扫这条街。
◆He has cleaned the street.
他已经打扫这条街了。
三、过去完成时
1．过去完成时的构成为had＋done，表示过去某个时间之前已经完成的动作，即过去完成时的动作发生在“过去的过去”，句中有明显的参照动作或时间状语(before、after、by、up till)，过去完成时不孤立使用。
2．动词hope、expect、think、intend、mean、want、suppo、plan用过去完成时，表示未实现的愿望、打算或意图。
3．在“hardly(scarcely)...、”句型结构中，主句用过去完成时，从句用一般过去时，意为“一……就……”。美剧排行
4．by、by the end of、by the time、until、before、since后接表示过去某一时间的短语或从句时，主句用过去完成时。
5．表示“第几次做某事”时，主句用一般过去时，从句用过去完成时。
◆Tom and I became friends in 2020，although we had met veral years before.
汤姆和我在2020年成为朋友，尽管在几年前我们就见过面。
◆I had intended to call on you，but I had an unexpected visitor.
我本来打算去看你，但是我有一位不速之客。
◆Hardly had the speaker finished his speech when the audience kept asking him questions.
演讲者一结束他的讲话，观众就不停地向他提问。
◆That was the cond time that she had en her grandfather.
那是她第二次看见她的祖父。
四、过去完成进行时
过去完成进行时的构成为had＋been＋doing，主要表示过去某一时间以前一直在进行的动作或表示动作在过去某一时间之前开始并延续到过去某一时间，这一动作可能已经停止也可能还在进行。
◆When Alice came to herlf，she did not know how long she had been lying there.
当艾丽丝苏醒过来的时候，她不知道自己已经在那儿躺了多久。(表示lie这一动作先于did not know，且lie这一动作还在进行)
◆She told me that she had been studying French for 5 years.
她告诉我她已经学习法语5年了。(动作仍继续)
迈克尔杰克逊 mp3
◆She told me that she had been waiting for me for an hour.
她告诉我她已经等我一个小时了。(动作不再继续)
注：
过去完成时和过去完成进行时的区别：
(1)过去完成时：表示动作在过去的某一时间或某一动作之前已经完成。
◆Tom was disappointed that most of the guests had left when he arrived at the party.
当汤姆到达派对现场的时候，大部分客人都走了，他很失望。
(2)过去完成进行时：表示在过去某一特定时间以前发生的动作一直持续到这个特定时间，或者刚刚结束，或者还要延续。但是，绝不会延续到现在。
英语 口语◆It had been raining hard for three weeks.Nearly all the little trees on the mountain were washed away.
大雨一连下了三个星期，山上的小树差不多都给冲走了。
特别提醒：时间点的确定以及是否强调动作的持续性是判断完成时态和完成进行时态的关键。
单元语法专练
Ⅰ.单句语法填空
1．(2021·浙江卷6月)It doesn't impress like George Washington's plantation on the Potomac, but Lincoln's home in downtown Springfield, Illinois, has__proved/proven(prove) irresistible to visitors since it opened to the public.
2．(2019·全国卷Ⅱ)For the past two years, Gordon's students have__been__studying(study) ways to kill bacteria in zero gravity.
3．The twins，who had__finished(finish) their homework, were allowed to play badminton on the playground.
4．During his stay in Xi'an, Jerry tried almost all the local foods his friends had__recommended (recommend).
5．I was arching for the three western lowland gorillas (大猩猩) I had__been__obrving(obrve).
6．But latter I found out that I had__been__doing(do) exactly the same thing.
7．You look thin and tired. You have__been__working(work) too hard recently.
8．Up to now, we have__finished(finish) most of the work, and the rest needs to be done in two days.
Ⅱ.语法与写作
crusher
1．The__film__had__begun(电影已经开始了) when they arrived at the cinema.
2．The__students__had__left__the__classroom(学生们已离开教室了) when the teacher came
in.
3．The roads were full of people. We__hadn't__thought__of__that(我们没有想到这一点).
resistive4．This rearch has__done__much__to__advance(大大提高了) our understanding of language lea
rning.
5．Robots have__been__doing__some__jobs(一直在做一些工作) on production lines since the 1960s.
