时间:2022-06-23 10:12:39
情态动词表推测的用法是高考的命题热点,也是同学们的学习难点。许多同学对表推测的情态动词混淆不清,做题时把握不准。为了帮助同学们更好地区分这类动词,下文将从不同角度剖析这一语法难点,并结合高考试题提供相应的应试策略。
英语中常用来表示推测用法的情态动词有:must,can,could,may,might,should等。可以从以下三个角度对它们加以区分:
一、 从不同的句式
情态动词表猜测的用法是有句式限制的。情态动词在不同的句式中的使用具体见下表。
从上表我们可以清楚地看到:must只用于肯定句;may/might一般不用于疑问句;而can多用于否定句、疑问句,用于肯定句时,多指“理论上的可能性”或“有时候的可能性”。
例如:Even expert drivers can make mistakes. 甚至是很熟练的驾驶员也可能会犯错。(理论上的可能)
The World Wide Web is sometimes jokingly called the World Wide Wait because it can be slow. “万维网”有时被戏称为“万等网”,因为网速有时会很慢。(有时候的可能性)
【考例探究】
1. I can’t find John everywhere. Where
_____________ he have gone?
A. can B. must
C. should D. would
【解析】本句为疑问句,而且表示推测。B项表示肯定的推测,常用于肯定句中;C项也不用于疑问句的推测;D项表示过去习惯(做某事)。故选A。
2. Cars play an important role in modern life, but they_____________ also cause many problems like air pollution.
A. should B. can
C. must D. will
【解析】情态动词can可用于肯定句中,表示有时候的可能性。故选B。
二、 从语气的强弱
根据说话人对推测对象的把握程度以及所进行的肯定与否定的推测,借用数学中“大于号”的形式,可以形象地将它们的用法区别表现出来。表示肯定的猜测时,各情态动词语气强弱如下:must>may>might;表示否定的猜测时,can’t>couldn’t>may not>might not。
例如:He doesn’t like driving on rainy days. He must be coming by bus. 他不喜欢下雨天开车;他一定是乘公共汽车来。(肯定推测,把握很大)
She might not like the idea. 她或许会不赞成这个想法。(肯定推测,把握较小)
The man standing there can’t be Mr. Zhang. Mr. Zhang has just gone to Beijing. 站在那儿的那个男人不可能是张先生。张先生刚刚到北京去了。(否定推测,把握很大)
解题时,如果题干中有客观依据,应该选择猜测语气最强的情态动词;如果没有客观依据,则应选择猜测语气较弱的情态动词。
【考例探究】
1.(2011北京卷)―I don’t really like James. Why did you invite him?
―Don’t worry. He_____________ come. He said he wasn’t certain what his plans were.
A. must not B. need not
C. would not D. might not
【解析】本题中根据“he wasn’t certain”可知因为James不确定自己的时间安排,那么说话人也不能确定James是否会来。因此,应选择表示否定推测的D项。A项意为“禁止,不可以”、B项意为“不需要”、C项表示肯定不来,皆不符合语境。
2.(2010浙江卷)“You_____________ have a wrong number,” she said. “There’s no one of that name here.”
A. need B. can
C. must D. would
【解析】本题中根据说话人所给出的充足的理由“There’s no one of that name here.”可知说话人对推测的事情把握较大,所以选C项must(肯定,一定)。
3.(2011江西卷)It_____________ be the postman at the door. It’s only six o’clock.
A. mustn’t B. can’t
C. won’t D. needn’t
【解析】本题中根据说话人所给出的充足的理由“It’s only six o’clock!”可知说话人对推测的事情把握较大,can’t在否定推测中语气最强,应选择B项。
三、 从事情发生的时间
表示推测的情态动词后面所接动词形式,有四种情况:
1. 情态动词+do,表示对现在或将来情况的推测。
例如:I don’t know where she is; she may be in Wuhan. 我不知道她在哪儿,可能在武汉。
2. “情态动词+be doing”,表示对现在或将来正在进行的情况进行推测。
例如:At this moment, our teacher must be correcting our exam papers. 这时,想必我们老师正在批改试卷。
3. 情态动词+have done时,表示对过去情况的推测。
例如:The road is wet. It must have rained last night. 地是湿的,昨天晚上一定下雨了。
4. 情态动词+have been doing,表示对过去某时刻正在发生事情的推测。
例如:Your mother must have been looking for you. 你妈妈一定一直在找你。
解题时,可以根据被猜测动作发生的时间,确定情态动词时态正确的形式。
【考例探究】
1.(2010安徽卷)Jack described his father, who_____________ a brave boy many years ago, as a strong-willed man.
A. would be B. would have been
C. must be D. must have been
【解析】由句中的many years ago可知是对过去的推测,故排除A、C;而B项表示可能性很小,故被排除。答案为D。
2.(2009江苏卷)He did not regret saying what he did but felt that he_____________ it differently.
A. could express
B. would express
C. could have expressed
D. must have expressed
【解析】由句中的what he did可以看出是对过去情况的推测,应该用“情态动词 + have done”的形式,故排除A、B两项;must have done sth.意为“过去本该做某事(而没做)”,故排除D项。could have done sth. 本可以做某事。答案为C。
3.(2009重庆卷)―Hi, Tom. Any idea where Jane is?
―She_____________ in the classroom. I saw her there just now.
A. shall be B. should have been
C. must be D. might have been
【解析】由句中的where Jane is可知是对现在的推测,且题干中有“I saw her there just now”,所以选择C项。
综上所述,只要从上述三个方面(句式、语气及事情发生的时间)区分表示推测的情态动词,我们就可以轻松解题,避免失分。
练一练
一、 根据所给中文提示完成下列句子,每空一词。
1. 明天你到那里时,他可能会在等着你。
He____________________________________________________ you when you get there tomorrow.
2. 他们会把房门钥匙藏到哪儿去呢?
Where_____________ they__________________________ the key to the room?
3. 如果火车准点的话,他们应该到北京了。
If the train arrives on time, they_____________
_____________ in Beijing now.
4. 你英语那么棒,你肯定学英语很多年了。
Your English is really good; you_____________
_______________________________________ English for many years.
二、 单项填空。
1. ―Everyone in my class passed the exam.
―Oh, really?It_____________ difficult.
A. can’t have been
B. needn’t have been
C. must be
D. mightn’t be_____________
2.(2009安徽卷)Some people who don’t like to talk much are not necessarily shy;they_____________ just be quiet people.
A. must B. may
C. should D. would
3. ―Why didn’t you answer the phone last night?
―I_____________ when you called.
A. had to have slept
B. had to be sleeping
C. must have been sleeping
D. must have slept
4. ―Why hasn’t Jack come back yet?
_____________ anything have happened to him?
―I’m not sure, but I guess something
_____________.
A. May; must have
B. Can; may have
C. Must; may
D. Dare; might have
5. “Hi, Mum! I’m on the bus, I _____________ be home in about ten minutes.”
A. would B. can
C. should D. may
Keys:
一、 1. may/might be waiting for;
2. could, have hidden; 3. should be;
4. must have been learning
二、 1-5 ABCBC