情态动词shall

情态动词shall ,will ,should和would 在不同的句子中含有不同的意思，其基本用法如下：

一、shall

1. 表示说话者的意图、允许、警告、命令、决心等，用于陈述句的第二、第三人称中，有必须，应，可之意。例如：

１）You shall have that book tomorrow.

2) He shall be punished if he insists on doing that.

2,. 在问句中表示征求对方意见，主要用于第一、第三人称，有“…..好吗”，“要不要”等意思。例如“

1) Shall I fetch the hammer?

2) Shall those goods be sent over to you at once?

3) Shall we help you?

2. 用在表示意图、要求等的从句中，有“应该”，“要”之意，例如：

My demand is that is shall be done in time.

二、should

1.表示义务、责任、建议或劝告，有“应当、应该”的意思。例如：

1) You should learn from each other.

2) You shouldn’t be so careless.

3) He should have told me the news earlier.

(should + have + 过去分词)表示对过去本该做的事而没有做，其否定形式是对过去本不做的事而做了的固定句型。

２．与why ,who ,how等词连用，表示意外、惊异等，有“竟会”等意思。例如：

1) How should I know?

2) Why should you be so late today?

３．用于表示建议、命令、决定等的从句中，有“应该、必须”的意思。例如：

1) The young doctor proposed that he should try the experiment on himself.

2) It was decided that we should start a cleanup at once.

４。表示可能性、推测或推论，有“可能、该”等意思。例如：

They should have arrived in Beijing by this time.

５．用于虚拟语气句子中，有“万一、竟然、就、该”等意思。例如：

1) Should it rain tomorrow (或If it should rain tomorrow ) ,the meeting would be postponed.

2) If the book were in the library ,you should have it. (should 在句子里表说话人的意愿)

三、will

１．表示意志、意愿，有“愿、要”之意。例如：

1) We will fight on until final victory is won.

2) I will do my best to help you.

3) She will not shove the heavy load on to others.

２．在疑问句中用于第二人称，表示说话人向对方提出请求或询问对方的意思，有“你…..好吗、你愿…..”。例如：

1) Will you help me with my work?

2) Will you join our discussion?

３．表示习惯、经常性、倾向性，有“惯于、总是”等意义。例如：

Every morning he will have a walk along this river.

４．在if ,when ,until等连词引导的表示时间或条件的从句中要用一般时表将来，但在if 从句中有时为了表示意愿也可用will ，有“愿意”的意思。例如：

1) If you will read this article ,you will realize you are wrong.

2) If they won’t help us ,we can not finish the task within one month.

四、would

１．Will 的过去式，表示对过去时间的意志、意愿、决心，有“愿、要、偏要”的意思。例如：

1) I promised that I would do my best.

2) I told him not to go ,but he would not listen to me.

２．表示请求或个人的想法、看法，使语气婉转，有“愿、倒”等意思，例如：

1) Would you please take a seat?

2) Would you mind opening the window?

3) I would like to express my thanks to you.

３．表示过去习惯性的动作，着重动作的重复，有“总是、总会”等意思。例如：

On Sundays he would come to our village and work with us.

４．表示虚拟、假设、条件等，有“要、将要、会、就会”等意思。例如：

1) If you had come earlier ,you would have seen him.

2) It would be better to adopt the new method.

[示例]

考题１It is nearly seven ,Jack ____ be here at any moment. (NMET1995)

A. must

B. Need

C. Should

D. can

解析这是带与语境的句子，从第一句的句意，我们便可以了解到＊第二句属推测句型，这样可排除选项Ｂ，在推测句型中否定句和疑问句中，故选Ｃ为正确，should 表示可能性的推测。

［训练］

单项选择填空：

1. ______read the letter for you?

A. would you like me

B. Do you want me

C. will you mind me

D. shall I

2. He promised he ____not make such silly mistakes.

A. would

B. Should

C. Will

D. shall

3. You are thirsty ,aren’t you? _____he get you some coffee?

A. will

B. Shall

C. Will

D. should

4. You say you ____not do it ,but I say you _____ do it.

A. will ;shall

B. Shall ;shall

C. Shall ;will

D. will ;will

5. ______your answer ,please? I didn’t quite catch you.

A. should you repeat

B. Are you doing to repeat

C. will you repeat

D. are you repeating

should 用法

should 一词在中学英语课本中出现频率很高。它的用法灵活、含义丰富，因而一直是历年高考关注的热点。现将其具体用法分述如下：

1. should 作为助动词shall 的过去式，可以在间接引语中与第一人称主语搭配，表示过去将来时间。例如：

1) The group leader announced that we should（= would）begin to work soon.

小组长宣布：我们不久就开始工作。

2) A week ago, I told him that I should（= would）go to Beijing the next day.

一个星期以前，我告诉他我第二天就去北京。

2. should 作为情态动词，通常用来表示现在或将来的责任或义务，译作“应该”、“应当”，这时它可以和ought to, be supposed to 互换使用。例如：

1) You should（= are supposed to ）complete your test in time.

你们应该按时做完你们的实验。

2) You should（= ought to ）tell your mother about it at once.

你应该立即把此事告诉你妈妈。

3. should 作为情态动词，可以用在条件状语从句中，表示语气较强的假设，译作“万一”、“竟然”，这时也可将should 置于从句之首，即将should 放在主语前面，而省略从属连词if .例如：

1) If anyone should come, say I am not at home.

= Should anyone come, say I am not at home. 万一有人来访，就说我不在家。

2) If it should rain tomorrow, I wouldn't go.

= Should it rain tomorrow, I wouldn't go. 万一明天天下雨，我就不去了。

4. should 作为情态动词，可以表示谦逊、客气、委婉之意，译为“可…”、“倒…”。例如：

1) I should say that it would be better to try it again. 我倒是认为最好再试一试。

2) You are mistaken, I should say. 据我看，你搞错了。

3) He should expect their basketball team to win the match.

他倒是希望他们的篮球队赢得这场比赛的胜利。

4) Should you like some tea ？你可喜欢喝茶？

5. should 作为情态动词，可以用来表示意外、惊喜或者在说话人看来是不可思议的。尤其在以why, who, how 等开头的修辞疑问句或某些感叹句中常常译为“竟会”、“居然”。例如：

1) How should I know it？我怎么会知道这件事？

2) Why should you be so late today？你今天怎么来得这么晚？

3) When I went out, whom should I meet but my old friend Xiao Li！

当我出去时，想不到竟会碰见我的老朋友小李！

4) I don't see any reason why he shouldn't be happy. 我不明白为什么他居然不愉快。

6. should 作为情态动词，可以用来表示有较大可能实现的猜测、推论，通常译为“可能”、“总该…吧”，相当于be expected to .例如：

1) They should be home by now, I think. 我想现在他们总该到家了吧。

2) The report was written after a careful investigation, so it should be reliable.

这份报告是经过周密调查后才写成的，所以应该是可*的。

7. should 作为情态动词，用在由so that, for fear that, lest (conj.∕prep. 惟恐,以免) 引导的目的状语从句和in case（that）引导的条件状语从句中，有“能够”、“可能”、“会”之意。例如：

1) They got up early so that they should（= could/ might）catch the first bus in time.

他们起得很早以便能及时赶上头班公交车。

2) He is working hared for fear that he should fall behind others.

他努力工作，唯恐落在别人后面。

3) We went over the document again and again lest we should miss any of the main points.

我们把文件看了一遍又一遍，唯恐忽略了其中的什么要点。

4) He took an umbrella in case（that）it should rain.

他带了一把雨伞，以防天下雨。

8. should 作为情态动词，可以用于下列虚拟语气句中：

1) 用在表示与将来事实相反的条件状语从句中，构成“ If…should（do sth）…，… would/

could/ might（do sth.）… ”句式。例如：

If it should（或were to）rain tomorrow，the sports meeting would be put off.

= Should it rain tomorrow/ Were it to rain tomorrow, the sports meeting would be put off.

如果明天天下雨，运动会就会延期举行。

2) 用在suggest, propose, arrange, plan, decide, advise, order, demand, request, desire, insist 等表示“建议”、“要求”、“命令”、“决定”、“安排”、“计划”、“主张”的动词后面接的宾语从句中。这里的should 也可以省略。例如：

①He suggested/ proposed/ demanded/ advised that they（should）read the rules carefully.

他建议/ 提议/ 要求/ 劝告他们要仔细阅读这些规则。

②The doctor ordered that she（should）stay in bed for another week.

医生嘱咐她再卧床休息一个星期。

③He insisted that we（should）take up the matter at the meeting.

他坚持要我们在会上提出这个问题。

3) 用在“ It is desired∕suggested∕requested∕ordered∕proposed∕decided”之后由that 引导的主语从句中, should 也可以省略。例如：

①It is requested that Miss Yang （should）give a performance at the party.

人们要求杨小姐在聚会上表演一个节目。

②It has been arranged （planned）that they （should）leave the following week.

已经安排（计划）让他们下星期动身。

③It has been decided that the meeting （should）be postponed till next Saturday.

已经决定会议推迟到下周六举行。

4) 用在suggestion, motion, proposal, order, plan, idea, advice, request, decision, requirer(需求) 等名词后面接的表语从句或同位语从句中, should 也可以省略。例如：

①We all agreed to his suggestion （proposal）that we （should）go to Nanjing for a visit.

我们都同意他提出的要我们到南京去游览的建议。（should 用于同位语从句中）

②My idea/ motion/ advice/ is that we（should）do more eye exercises every day.

我的意见是我们每天应该多做眼保健操。（should 用于表语从句中）5）用在“It is∕was necessary∕important∕strange∕incredible”或“It is a pity∕a shame∕no wonder”之后由that 引导的主语从句中，should 有“应该”、“必须”、“竟然”、“居然”之意。例如：

①It is necessary that he （should）be sent there at once. 有必要马上派他到那里去。

②It is strange that the wheel should turn so slowly.

真奇怪，这个轮子竟然转动得如此之慢。

③It is a great pity/ shame/ that he should be so conceited. 真遗憾，他竟会这样自高自大。

9.“should have + —ed 分词”结构用来表达下述意义：

1) 表示“应该已经…”，“本来应该…”，即过去该做某事但实际没有做，其否定式“shouldn't have + —ed 分词”意为“本来不应该…”。例如：

①These cells should have been kept in some dry places.

这些电池本来应该放（保存）在干燥的地方。（但实际上没有把它们放在干燥的地方。）

②You shouldn't have dept those cells in the damp place.

你本来不该把那些电池放在潮湿的地方。（但实际上已经把它们放到潮湿的地方了。）

2) 表示“（估计）应该已经…”，“大概已经…”，即对过去情况的推测。例如：

①They left at nine, so they should have arrived（= probably have arrived）home by now.

他们是九点钟走的，现在应该已经到家了。

②They should have finished their work，for they began to do it so early.

他们很早就开始工作，现在大概已经干完了。

3) 意为“竟然已经…”，“居然已经…”，即表示说话人对已经出现的事态感到“惊奇、惊喜、怀疑”。例如：

①I'm surprised that he should have been so foolish. 我很奇怪，他竟然会这么傻。

②I'm amazed that Mr Harris should have said nothing about the matter.

这件事，哈里斯先生竟然只字未提，对此我大为惊异。

③It is wonderful that you should have achieved so much these years.

这几年你竟然取得如此大的成就，你真了不起。

10. should 还可以出现在“should be doing sth”或“should have been doing sth”等句式中，表示“应该正在…”或表示说话人的某种不满情绪。例如：

①Why should we be sitting here doing nothing？我们干嘛坐在这里闲着？

②You should be wearing a mask. 你应当戴着口罩。

③She shouldn't be working like that. She is still so weak.

她不应当那样干。她身体还很虚弱。

④You should have been waiting for us. Why haven't you？

你应当等着我们的。怎么没有等？