内容正文:
Period 3 Discovering Useful Structures
情态动词和过去将来时
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要义详析 探究语法
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课堂微练 即时检验
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内
容
索
引
要义详析 探究语法
PART
01
第一部分
一、情态动词的特点
情态动词本身有一定的词义,通常与动词原形一起构成谓语,表示说话人对某一动作或状态的态度或主观设想。
1.在意义上,情态动词有一定的词义,但不能单独作谓语,需和实义动词或系动词一起作谓语;
2.在形式上,情态动词一般没有人称和数的变化(be able to、have to除外);
3.在用法上,情态动词与助动词一样,其后需接动词原形,构成谓语动词。
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二、情态动词的基本用法
(1)(教材P52)Oliver believes that with a million-pound bank note a man could live a month in London. 奥利弗认为一张面值百万英镑的钞票能让一个人在伦敦生活一个月。
(2)(教材P52)May we ask what you're doing in this country and what your plans are?
能告诉我们你来这个国家干什么吗?你有什么计划吗?
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(3)You must finish your homework this afternoon.
你必须在今天下午完成你的作业。
(4)I promise I will do my best to provide the best service for the Asian Games.
我保证我会尽我所能为亚运会提供最好的服务。
(5)He needn't have gone to hospital, but he went just to reassure himself.
他本不必去医院的,去了只是想让自己放心。
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(6)I dare not hand this project over to anyone else.
我不敢将这个项目交给其他任何人负责。
(7)She can't have been to your house; she doesn't know your address.
她不可能去过你家,她不知道你的地址。
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1.can/could
(1)表示能力,指有能力做某事。could为can的过去式;
(2)表示请求或允许。could比can语气更加委婉,当表示给予允许或同意时通常不用could;
(3)表示推测,意为“可能”,常用于否定句和疑问句中,can't/couldn't意为“不可能”;
(4)表示一时的可能性,意为“有时会”,常用于肯定句中。
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2.may/might
(1)表示请求、允许或许可。might在语气上比may更加委婉。以may/might开头的问句在否定回答中要用mustn't;
(2)表示把握不大的推测,意为“可能、也许”,用于肯定句或否定句中,might语气更加不确定;
(3)用于祈使句,表示祝愿;
(4)“may/might as well+动词原形”是固定结构,意为“不妨……”。
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3.shall/should
(1)shall
①用于第一、三人称的疑问句中时,表示征求意见;
②用于第二、三人称的陈述句中时,表示允诺、命令、警告和强制,或表示说话人的决心等;
③在法律、条约、协定等文件中,表示义务、规定等。
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(2)should
①表示责任和义务,意为“应该”;
②表示推测,指有一定根据的推测,意为“按道理应该”;
③表示惊讶,意为“竟会、居然”。
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4.must
表示现在或将来必须要做某事,多是出于义务、责任或强制命令,指说话人的主观意志。其否定形式为mustn't,意为“一定不要、不准、禁止”。
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(1)回答must引导的问句时,如果是否定的回答,要用needn't或don't have to;
(2)must表示“偏要、硬要”,指不愉快的事;
(3)must表示推测,其推测的可能性比较大,意为“一定、必定”,常用于肯定句中。
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5.will/would
(1)will表示意愿、意志,would表示过去时间的意愿、意志。
(2)表示征求意见或提出请求,主要用于第二人称疑问句中,will和would均可使用,would此时不表示过去,而是表示委婉语气。
(3)will表示某种倾向或习惯性动作,意为“总会、老是”;would表示过去反复发生的动作或过去的一种倾向。
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6.need和dare
(1)need表示必要性,意为“需要”;dare表示敢于。need和dare作情态动词时常用于否定句、疑问句或条件句中,无人称和数的变化,疑问句和否定句中不加助动词;
(2)need和dare用作实义动词时,有词形变化;在否定句、疑问句中要加助动词。
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7.情态动词+have done
形 式 用 法 例 句
must have done 对过去的肯定推测,意为“过去肯定做了” *It must have rained last night, for the road is quite wet.
昨晚肯定下雨了,因为路面十分潮湿。
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形 式 用 法 例 句
can't/couldn't have done 对过去的否定推测,意为“过去不可能做了” *He couldn't have known the decision, for no one told him.
他一定不知道这个决定,因为没人告诉他。
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形 式 用 法 例 句
could have done 意为“本来能够做而没做” *You could have made greater progress, but you didn't try your best.
你本能够取得更大的进步,但是你并没有尽全力。
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形 式 用 法 例 句
may/might (not) have done 意为“可能(没有)做过” *You may have dropped it when you were shopping in the market.
你或许是在市场买东西的时候把它掉了。
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形 式 用 法 例 句
ought to/should have done 意为“本来该做而没做” *You should have come to school if you were really serious about your study.
要是你真的认真对待学习的话,你本应该来上学的。
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形 式 用 法 例 句
ought not to/should not have
done 意为“本来不该做而做了” *I should not have eaten so much cake at the party.
我本不应该在派对上吃那么多蛋糕的。
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形 式 用 法 例 句
needn't have done 意为“本来不必做却做了” *You needn't have telephoned him, for he had known the result.
你本不必打电话给他,因为他已经知道结果了。
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三、过去将来时
(1)(教材P52)Young man, would you step inside a moment, please?
小伙子,请进来一下,好吗?
(2)(教材P52)Yes, I was about to go get the letter.
好的,我正要去拿信。
(3)She told her mother that she was leaving for a ball with Mike.
她告诉母亲,她要和迈克一起去参加一个舞会。
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过去将来时的表示方法:
1.would/should do:表示从过去某一时间来看将要发生的动作或存在的状态。
2.was/were going to do:表示过去将要发生或很有可能发生的动作,常用于口语中,表示意图或者打算等。
3.was/were about to do:常用来表示即将发生的动作,表示“刚要/正要做……”。注意该结构不与任何时间状语连用。
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4.was/were to do:表示“曾计划做某事”,也可以表示“命中注定要发生的事”;如果表示“本来计划做某事,动作没实现”,则需用“was/were to have done”。
5.was/were doing:常用动词有start、go、come、leave、see、meet等,表示就过去某一时刻而言即将发生的动作。
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课堂微练 即时检验
PART
02
第二部分
Ⅰ.单句语法填空
1.He _________ go to the river nearby to fish on weekends when he was young.
2.The report is written after careful investigation. So it _________ be reliable.
3.When he was young, he _________ climb the small hill every morning.
4._________ you please be kind enough to tell me something about that?
would
should
would
Could
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5.I have reached a point in my career where I _________ to decide which way to go.
6.If you can pass the driving test, you _________ get a new car.
7.She _________ have been caught in the heavy traffic. If so, she won't arrive here by five o'clock.
8.One of our rules is that every student _________ wear school uniforms while at school.
need
shall
may/might
shall
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9.You _________ as well walk outside with your friends or take some exercise.
10.It is not a problem whether we _________ win the battle; it's just a matter of time.
11.He said that if it didn't rain he _________ (go) to the park.
12.It is usually warm in winter in the south, but it _________ be cold and even have snow sometimes.
may/might
can
would go
can
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13.Despite all our efforts to persuade him, he still _________ not change his mind to quit his job.
14.I'm not a trained musician, but I've learnt to read music so I _________ help Maria in her performance.
would
can
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Ⅱ.语法与写作
1.我想不起来了——我当时一定是失去了知觉。
I can't remember any more—I _____________________ consciousness.
2.我刚穿上外套要去看望我的一个朋友。
I had just put on my overcoat and _____________________a friend of mine.
must have lost
was leaving to visit
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3.你本来能早点通过考试,但你如此粗心,以至于犯这么多错误。
You ___________________________________, but you were so careless as to make so many mistakes.
4.看看你都做了什么!你本应该更仔细地做这个实验。
Look what you've done! You ____________________________the experiment more carefully.
could have passed the exam early
ought to/should have done
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5.周五我们的老师告诉我们,他打算带我们去观看一场辩论赛。
On Friday our teacher told us that _____________________________
a debate competition.
6.那个测试很容易,他本来应该通过的,但却没有。
It was an easy test and he _____________________, but he didn't.
he was going to take us to watch
should have passed
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7.她可能买了那本词典,但我不确定。
She _____________________ the dictionary, but I'm not sure.
8.你本没必要订票的,因为这几天动物园免费向公众开放。
You _____________________the ticket, for the zoo is open to the public free of charge these days.
may have bought
needn't have booked
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