一、动词的时态
（一）一般体
一般体中的一般现在时、一般过去时分别表示现在、过去的经常性、习惯性动作或状态; 一般将来时表示将来某一时刻的动作或状态, 或将来某一段时间内经常发生的动作或存在的状态; 过去将来时表示从过去某一时间看将要发生的动作。所谓一般体, 表示既不“进行”, 又不“完成”。
We have meals three times a day.
我们一日吃三餐。(现在的习惯)
He is always ready to help others.
他总是乐于助人。(现在的状态)
When I was a boy, I often went to play in that park.
我小时候常去那个公园玩。(过去的习惯)
1. 一般现在时
(1)一般现在时的构成
1)一般现在时主要用动词的原形表示, 如果主语为第三人称单数, 则一般在动词原形后加⁃s 或⁃es, 其变化规则如下表所示:
2)be 的变化:am, is, are。
3)have 的变化:has, have。
(2)一般现在时的用法
一般现在时除了可以表示现在的经常性、习惯性动作或状态外, 还可表示:
1)一般现在时表示客观真理、科学事实及自然现象。此用法即使出现在过去语境中, 也用一般现在时。
The sun rises in the east. 太阳从东方升起。
2)用于here, there 开头的倒装句中, 一般现在时表示现在正在发生的动作或存在的状态。
There goes the bell. 铃响了。
Here comes the bus. 公共汽车来了。
2. 一般过去时
(1)一般过去时的构成
1)一般过去时用动词的过去式表示, 其规则动词变化方法如下表所示:
2)was 用于第一、三人称单数, were 用于其他人称。
3)注意以元音字母加y 结尾的动词, 直接加⁃ed。如:play→played。
(2)一般过去时的用法
一般过去时除了可以表示过去经常性、习惯性的动作或状态外, 还可表示:
1)want, hope, think, intend 等动词的一般过去时往往表示“过去原……”之意。
I thought he was an honest man. 我原以为他是个老实人。
He didn't intend to hurt you. 他没打算伤害你。
2)wonder 的一般过去时有时也可表示现在的行为, 但口气要比用一般现在时更加委婉、客气。
I wondered if you could do me a favour.
我不知道你能否帮我一个忙。
3)used to + 动词原形, 表示过去的习惯性动作而现在已经不再发生了。
We used to spend our vacation in the mountains.
我们以前常常在山里度假。(暗示现在不再在山里度假了)
3. 一般将来时
(1)一般将来时的构成
1)shall + 动词原形(第一人称)
2)will + 动词原形(各种人称)
(2)一般将来时的用法
一般将来时除了可以表示将来的动作或状态外, 还可表示:
1)will + 动词原形
①will 可用来表示事物的固有属性或必然趋势。
Fish will die without water. 离开水, 鱼就会死。
②will 表示将来, 有时含偶然性、临时性决定的意思。
—Do you know Mr. Smith has come to our town?
—No. I will go and visit him right now.
———你知道史密斯先生来我们镇了吗?
———不知道。我现在就去看他。
2)be going to + 动词原形
“be going to + 动词原形”多用在口语中, 表示“计划、打算要做某事”, 此外, be going to 还可表示根据现在的迹象对未来进行推断。
He is going to speak on TV this evening.
他今晚要在电视上讲话。
Look at the dark clouds. It is going to rain.
看这些乌云, 要下雨了。
注意:was going to 还可表示“过去本打算做某事, 但未做”的意思。
—Tom, you didn't come to the party last night?
—I was going to, but I suddenly remembered I had homeworkto do.
———汤姆, 你昨天晚上没来参加聚会吗?
———我本打算要来的, 但是我突然记起来我有作业要做。
3)be about to + 动词原形/be on the point of + 动名词“be about to + 动词原形”及“be on the point of + 动名词”表示“立即的将来(immediate future)”, 因此, 这两种结构不与表示将来的具体时间状语连用, 但可以和并列连词when(=and at that time)引出的分句连用。
The train is about to start. 火车就要开了。
The plane is on the point of taking off.
飞机马上就要起飞了。
4)有些动词如come, go, arrive, leave, begin, start 等, 其现在进行时表示按计划、安排近期将要发生的动作。
I'm leaving for Beijing next month. 下个月我要去北京。
5)某些动词的一般现在时可以表示计划、安排将要做的事情, 这种用法常常用于火车时刻、飞机时刻、电影开演、作息安排等时刻表上。
We must hurry up. The first class begins at 8 o'clock.
我们必须快点。第一节课将在8 点开始。
6)be to + 动词原形
①表示“按计划或安排要做的事”。
When are you to leave for home?
你什么时候回家?
She is to get married next month.
她将于下个月结婚。
The Queen is to visit Japan in a week's time.
女王将于一周后访问日本。
这种结构也可用于过去时。was/were to do sth. 表示曾经计划要做的事, 但不表明计划是否被执行, 或表示命运(即命中注定要发生的事); was/were to have done sth. 表示未曾实现的计划。
I felt nervous because I was soon to leave home for the first time. 我感到紧张, 因为我很快就要首次离开家了。
They said goodbye, little knowing that they were never to meet again. 他们告了别, 一点也没想到以后再也不会见面了。
We were to have told you, but you were not in.
我们本来想告诉你的, 但是你不在家。
②表示“应该”, 相当于should, ought to。
You are to report it to the police. 你应该报警。
What is to be done? 应该怎么办呢?
③表示“想, 打算”, 相当于intend, want。
If we are to be there before ten, we'll have to go now.
如果我们要在10 点前到那儿, 我们现在就得走。
4. 过去将来时
(1)过去将来时的构成
should/would + 动词原形
(2)过去将来时的用法
过去将来时表示从过去某一时间看将要发生的事情。
He said he would be here at eight o'clock.
他说他将在八点钟到这里。
(二)进行体(表格未列出)
1. 进行体的构成
(1)考纲对进行体所要求掌握的时态包括:现在进行时、过去进行时、将来进行时, 它们的形式分别为:
现在进行时:am/is/are + 现在分词
过去进行时:was/were + 现在分词
将来进行时:will/shall + be + 现在分词
(2)现在分词的构成形式:
2. 进行体的用法
(1)进行体表示某一时刻或阶段内正在进行的动作或存在的状态, 具有暂时性和未完成性的特点。
I don't really work here; I am just helping out until the new secretary arrives.
我并不在这里上班, 我只是来帮忙, 直到新秘书来了(我就走)。(暂时性)
(2)表示某阶段正在进行的动作或发生的事, 虽然当时动作不一定正在进行, 常与these days, this week 等时间状语连用。
We are making model planes these days.
这些天我们在做飞机模型。(此时此刻不一定在做)
(3)表示反复出现的或习惯性的动作, 往往含有赞赏、厌恶、遗憾等情绪, 常与always, continually, constantly, forever, all the time 等连用。
He is always thinking of others first. 他总是先想到他人。
He is always making the same mistake. 他总是犯同样的错误。
(4) 有些动词的进行体可以表示将来。(见一般将来时的用法)
(5)有些动词不用于进行时态, 常见的有:
1)感觉类:look, smell, feel, sound, taste, see, hear 等。
The soup tastes good. (不可说:The soup is tasting good.)
这汤尝起来不错。
Your hands feel cold. (不可说:Your hands are feeling cold.)
你的手摸起来很凉。
2)情感类:like, love, prefer, admire, hate, fear, adore 等。
I love my dad and mum. (不可说:I am loving my dad and mum.) 我爱爸爸妈妈。
3)心态类:wish, hope, want, need, believe, understand, agree, know, remember, forget 等。
I don't believe my eyes. (不可说:I am not believing my eyes.)
我不相信我的眼睛。
4)存在状态类:appear, lie(位于), remain, belong, have 等。
Those books belong to Mr. Li. (不可说: Those books are belonging to Mr. Li.)那些书是李先生的。
(三)完成体
1. 完成体的构成
(1)考纲对完成体所要求掌握的时态包括:现在完成时、过去完成时、将来完成时。其形式分别为:
现在完成时:have/has + 过去分词
过去完成时:had + 过去分词
将来完成时:will/shall have done
(2)规则动词的过去分词的构成方法同过去式的构成方法, 详见一般过去时部分“规则动词变化方法”。
(3)不规则动词的过去式和过去分词构成详见“附录二”
2. 完成体的用法
(1)现在完成时
1)表示一个动作开始于过去, 持续到现在(也许还将持续下去)。表示从过去延续到现在并包括现在在内的一段时间的状语有:lately, recently, in the last/past few days/years(在过去的几天/年里), since then, up to now, so far(至今)等。
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。
He has written 8 books so far.
到目前为止, 他已经写了8 本书了。
2)表示发生在过去的事情对现在产生的影响, 注意这时说话者说话的重心在过去的事情对现在产生的影响上。常用的状语有:already, just(刚刚), yet, before 等。
He has turned off the light. (=The light is off now.)
他已经关掉灯了。
The concert has started. (=The concert is on now.)
音乐会已经开始了。
I have already seen the film. (=I know the film now.)
我已经看过那部电影了。
3)在“最高级 + 名词”或“It/This is + the first/second... time”之后的定语从句中, 谓语动词用现在完成时。
This is the first time(that)I have come here.
这是我第一次来这里。
This is the best tea(that) I have ever drunk.
这是我喝过的最好的茶了。
4)瞬间动词又叫非延续性动词、终止性动词。瞬间动词可以用于完成时态, 但不可以接表示一段时间的状语; 若要接表示一段时间的状语, 需要做一些相应的变换。瞬间动词的否定式可以接表示一段时间的状语。
(x)He has come to Beijing since last year.
(√)He has lived in Beijing since last year.
(x)He has joined the army for 3 years.
(√)He has served in the army for 3 years.
(√)He joined the army 3 years ago.
(√)He has been a soldier for 3 years.
(√)It is 3 years since he joined the army.
(√)He has joined the army.
常见的瞬间动词(词组)有:come, go, get to/reach/arrive at/in, leave, buy, sell, open, close, get up, join/take part in, begin/start, return/give, borrow/lend, become/turn, bring/take, die, finish/end, receive/hear from, marry, break, lose, jump 等。
部分非延续性动词(短语)和延续性动词(短语)的转换:
买buy—have
借borrow—keep
结婚get married—be married
认识get to know—know
离开leave—be away
回来come back—be back
生病fall ill—be ill
死亡die—be dead
关闭turn off—be off
打开turn on—be on
动身leave for—be off to
变成become—be
返回return—be back
开始begin—be on
睡觉go to bed—sleep
穿put on—have on/wear
来/去come/go—be in/away
参加join—be a member of
感冒take/get/catch a cold—have a cold
入睡go to sleep—be asleep
到达get to/arrive in(at)/reach—be in
(2)过去完成时
1)一件事情发生在过去, 而另外一件事情先于它发生(即表“过去的过去”), 那么发生在前的动词要用过去完成时。
She had learned some English before she came to the institute.
她在来这个机构前已学过一些英语了。
He said that he had been abroad for 3 years.
他说他在国外待了3 年了。
2)表示从过去某一时间开始, 一直延续到过去的另一时间的动作, 常用的时间状语有:by/until/before/by the end of + “表过去的某一时间”。
By then he had learned English for 3 years.
到那时, 他已学了3 年英语了。
Until then he had known nothing about it yet.
到那时为止, 他对此仍一无所知。
3)表示愿望、打算的词, 如:hope, expect, mean, intend, want, suppose 等, 其过去完成时表示过去未曾实现的愿望或意图。
I had hoped to see more of Shanghai.
我本希望在上海多看看。(但未能如愿)
I had meant to help you, but I was too busy at that moment.
我本打算帮你的, 但当时我太忙了。
I had thought you would come the next day.
我原以为你第二天会来。
4)用于某些固定句型中:
①Hardly/Scarcely/Barely... when... 和No sooner... than... 句型中, when 和than 从句里用一般过去时, 主句用过去完成时, 且用倒装, 表示“刚刚……就……”。
Hardly/No sooner had I got home when/than the rain poured down. 我刚到家, 大雨就倾盆而下。
Hardly had we started when the car got a flat tyre.
我们才刚刚开动, 汽车的轮胎就瘪了。
②It was/had been + 一段时间 + since 从句。since 从句的谓语用过去完成时。
It was ten years since we had had such a wonderful time.
我们有10 年没那么高兴过了。
③That/It/This was the first/second... time + that 从句。that 从句的谓语要用过去完成时。
It was the third time(that)he had made the same mistake.
那是他第三次犯同样的错误了。
That was the first time that I had passed the exam.
那是我第一次考试及格。
(3)将来完成时
将来完成时表示到将来某一时间某一动作将会完成, 常用的时间状语为“by + 将来的某个时间”。
By this time of next year, all of you will have become college students.
到明年的这个时候, 你们大家就都成为大学生了。
(四)完成进行体
1. 考纲对完成进行体所要求掌握的时态为现在完成进行时, 其形式为:have/has + been + doing。
2. 现在完成进行时是现在完成时和现在进行时的组合, 因此, 它既具备现在完成时的特征, 又具备现在进行时的特征, 如:它具备进行体的“未完性、暂时性、感情色彩”的特点。
He has been learning English for 6 years.
他学英语已经6 年了。(从过去某一时间开始学英语, 强调∙∙ 到现在还在学∙∙∙∙∙∙)
It has been raining for 3 days.
已经下了三天雨了。(强调说话者“抱怨”的感情色彩)
(五)动词时态的呼应
1. 主将从现
所谓“主将从现”, 即主句表将来(不一定为一般将来时, 祈使句、“情态动词 + 动词原形”也可表将来), 从句(包括时间、条件、让步状语从句)用现在时(不一定是一般现在时, 现在进行时、现在完成时也可在这类从句中表示将来)。
Whatever you say, I will not change my mind.
无论你说什么, 我都不会改变主意。
If she is still waiting, tell her to go home.
如果她还在等, 就让她回家。
I will go with you as soon as I have finished my work.
我干完了工作就和你一起去。
2. 含宾语从句的句子的时态一致问题
宾语从句中的动词时态常受主句谓语时态的制约, 如果主句谓语为现在时或将来时, 宾语从句中的谓语可以不受影响。
He says his father is/was/will be a teacher.
他说他父亲现在是/过去是/将会成为老师。
如果主句的谓语动词是过去时, 宾语从句的谓语动词一般需用过去的某种时态, 即一般过去时、过去进行时、过去完成时、过去完成进行时、过去将来时、过去将来进行时等。
I was sure he was in bed. 我确信他在床上睡觉。(be in bed与was sure 同时发生)
He thought he was working for the people. 他认为他正在为人民工作。(表示thought 发生时work 正在进行)
I wondered if she had got well. 我想知道她是否痊愈了。(get well 先于wondered 发生)
He wanted to know what she had been doing. 他想知道她一直在做什么。(do 从过去发生, 直至wanted 且在wanted 时还在进行)
I hoped I'd find a job soon. 我希望我不久就会找到工作。(find 在hoped 之后发生)
I thought she'd be going by bus. 我以为她会乘公交车去。(go by bus 在thought 之后发生)
注意:
(1)当主句为过去时, 宾语从句有明确的表过去的时间状语时, 可不必用过去完成时而用一般过去时。
I knew he was born in 1991. 我知道他生于1991 年。
(2)当宾语从句表达永恒的真理时, 谓语动词不必变为过去时, 而继续采用一般现在时态。
This proved that the earth is round. 这证明地球是圆的。
The teacher told us that the Yangtze River originates in Qinghai. 老师告诉我们长江发源于青海。
3. 含虚拟语气的句子中的时态一致问题
(1) 在“would (should/ought to/could/might/needn't/would like to 等) have done sth. , but...”句型中, but 后面的谓语动词需用一般过去时或过去进行时。
He should have turned up but he had an unexpected visitor.
他本应该到场, 但他那里来了一个不速之客。
(2)在“But for the fact that 从句”中, that 从句的谓语动词时态要根据后面句子谓语动词所表示的时间而定。
But for the fact that he is busy now, he would be here.
要不是他现在很忙, 他就在这里了。
But for the fact that you were ill, I would have had you print
the papers. 要不是你生病了, 我就让你去打印这些文件了。
(3)It is time + that 从句, that 从句中谓语动词需用一般过去时或should + 动词原形。
It is time that we went to bed.
我们该睡觉了。
(六)易混时态的区别
1. 一般过去时和现在完成时的用法区别
一般过去时所表示的一个或一段过去时间是可以具体确定的, 与其他时间没有牵连, 它所表示的事情纯属过去; 现在完成时说的是现在的情况。比较下面几组句子, 体会两种时态的不同:
He served in the army from 2005 to 2010. (这是过去的一件事)
He has served in the army for 5 years. (现在他仍在军中服役, 他仍然是名军人)
He wrote many plays when he was at college. (写剧本是他过去做的事情)
He has written many plays. (这意味着他现在是剧作家)
I saw Lost in Thailand last year. (看《泰囧》的时间是去年, 与现在无关)
I have seen Lost in Thailand before. (以前看过, 强调现在知道这部电影的内容。before“以前”是一个与现在有联系的时间, 而不是一个确定的与现在无关的过去时间)
2. 一般过去时和过去完成时的用法区别
(1)一般过去时是指过去的动作或情况, 而过去完成时指过去的一个动作或时间之前发生的事。
He had learned 3, 000 English words before he came to this school. 他来这个学校之前就已经学了3, 000 个英语单词了。
(2)过去完成时的时间状语常用by 或before 引导的短语或句子表示, 如by that time, by the end of, before 2010, by the time + 句子(一般过去时)等。
He had finished writing the book by the end of last month.
到上个月底为止, 他已经写完这本书了。
3. 过去完成时与现在完成时的用法区别
两种时态都常与表示一段时间的状语连用, 但现在完成时表示的是延续到现在或同现在有关的动作(句中不可有表示过去特定时间的状语), 而过去完成时表示的是在过去某时之前已经完成或延续到过去某时的动作(句中可有表示过去特定时间的状语)。比较下面的说法:
She had been ill for a week before she came back. (“回来”发生在过去某一时间, “生病”发生在这一时间之前, 即过去的过去)
She has been ill for a week. (现在仍然病着)
题组训练 用所给动词的正确时态填空
①(2015 天津, 6) Jane can't attend the meeting at 3 o'clock this afternoon because she will be teaching(teach)a class at that time.
②(2014 大纲全国, 32) The reports went missing in 2012 and nobody has seen (see) them since.
③(2014 北京, 22)—Hi, let's go skating.
—Sorry, I'm busy right now. I am filling (fill) in an application form for a new job.
④(2013 安徽, 24) I'm calling about the apartment you advertised (advertise) the other day. Could you tell me more
about it?
⑤(2013 浙江, 10) During the last three decades, the number of people participating in physical fitness programs has increased (increase)sharply.
⑥(2014 山东, 1) Writing out all the invitations by hand was more time⁃consuming than we had expected (expect).
⑦ (2014 山东, 5) They made up their mind that they would buy (buy) a new house once Larry changed jobs.
⑧(2014 浙江, 11) Sofia looked around at all the faces:she had the impression that she had seen (see) most of the guests before.
⑨(2012 湖南, 25)Close the door of fear behind you, and you will see (see)the door of faith open before you.
⑩(2012 江苏, 32)The manager is said to have arrived back from Paris where he had met (meet)some European business partners.
二、主谓一致
主谓一致即在句子中谓语动词的数必须和主语的数保持一致。一般可根据三个原则来确定:语法一致原则(主语的单复数决定谓语动词的单复数)、意义一致原则(形单意复的名词或形复意单的名词, 要根据其意义来决定谓语动词的单复数)、就近一致原则(谓语动词的单复数取决于离它最近的主语)。
(一)语法一致
1. 主语是单数, 谓语动词用单数; 主语是复数, 谓语动词用复数。
The results of the research are to be published soon. 研究结果不久将被发表。
His suggestion has been accepted. 他的建议被接受了。
2. many a + 单数名词(许多)/more than one(不止一个) + 单数名词作主语, 谓语动词用单数。
Many a student comes into the classroom. 很多学生进了教室。
More than one student wants to join the army. 不止一个学生想参军。
3. 复合不定代词anyone, somebody, everything, nothing, each等作主语, 谓语动词用单数。
If anyone sees Lisa, ask her to call me. 如果有人看到Lisa, 让她给我打个电话。
(二)意义一致
1. 形式为单数但意义为复数的police, cattle 等作主语时, 谓语动词用复数。
The police have not made any arrests. 警方未逮捕任何人。
2. 表示一类人的the poor/rich/dead/injured/wounded 等作主语时, 谓语动词用复数。
The rich are to help the poor. 富人应该帮助穷人。
3. 表示某国人的总称的the Chinese, the British, the Irish 等作主语时, 谓语动词用复数。
The Chinese are hardworking. 中国人民是勤劳的。
4. 以-s 结尾但意义为单数的news, maths, physics, politics 等作主语时, 谓语动词用单数。
The news is exciting. 这则消息激动人心。
5. 单复数同形的名词sheep, deer, means 等作主语时, 谓语动词的单复数与实际意义一致。
3 sheep are eating grass there. 3 只羊正在那里吃草。
A sheep is lying there. 一只羊正躺在那里。
Not every means is useful. 不是每种方法都好使。
6. 表示时间、距离、金额等的复数名词作主语, 通常看作整体, 谓语动词用单数。
Twenty years is a long time in one's life.
二十年在人的一生中是很长的一段时间。
20, 000 dollars is not a small sum of money.
两万美元不是一笔小数目。
(三)就近一致
either... or... , neither... nor... , not only... but also... , whether... or... 在句子中连接并列主语的时候或者在there be 句型中, 谓语动词的单复数形式要和就近的主语的单复数保持一致。
Neither you nor I am wrong. 你和我都没错。
There is a cup of tea and some apples on the table. 桌上有一杯茶和一些苹果。
Not only the students but also the teacher wishes for a holiday.
不仅是学生, 老师也盼望假期。
(四)主谓一致的几个难点
1. 并列主语的主谓一致
(1)两个单数名词或不可数名词用and 连接, 表示两个不同的概念时, 谓语动词用复数。
Steam and ice are different forms of water.
蒸汽和冰是水的不同形式。
(2)两个单数名词用and 连接, 表示同一人、同一物或同一个概念, 或表示不可分的整体时, 谓语动词仍用单数。
Trial and error is the source of our knowledge.
反复尝试是我们获得知识的源泉。
(3)被every, each, many a, no 等限定的名词由and 连接作主语时, 谓语动词仍用单数。
Each boy and each girl has an apple.
每个男孩和每个女孩都有一个苹果。
Many a teacher and many a student has seen the film.
许多老师和学生都看过这部电影。
(4)一个单数名词或不可数名词被几个用and 连接的并列形容词修饰时, 可以指一件事或几件事, 这种名词作主语时, 要根据意义一致的原则决定谓语动词的单复数形式。
English and American literature are appealing to her.
英国文学和美国文学都对她有吸引力。
Simple and plain living is a fine quality.
简朴生活是一种优良的品质。
2. 单数名词作主语, 后跟with, along with, together with, as well as, rather than, but, except 等加其他名词时, 谓语动词仍用单数形式。
Dr. Smith, together with his wife, is to arrive on the evening flight. 史密斯博士及其夫人将乘夜班飞机抵达。
Nobody but one teacher and three students was in the laboratory.
只有一个老师和三个学生在实验室里。
3. 某些名词作主语时的主谓一致
(1) 集体名词family, class, crew, team, group, public, audience, crowd, government, committee 等作主语时, 谓语动词的单复数形式要根据主语所指的意义而定。当把集体名词作为一个整体来看待时, 谓语动词常用单数形式; 如果指其中各个成员时, 谓语动词常用复数形式。
The class consists of twenty-five boys and twenty girls.
这个班由25 个男生和20 个女生组成。
The class are doing experiments.
全班学生正在做实验。
(2)由两部分构成的表示物体的名词, 如trousers, pants, jeans, compasses, glasses, shoes 等作主语时, 谓语动词常用复数形式。但如果这类名词前用了a pair of/two(three)... pairs of 来修饰, 谓语动词的单复数往往取决于pair 的单复数形式。
These trousers need cleaning. 这些裤子需要洗了。
This pair of trousers is mine. 这条裤子是我的。
4. 数词与量词作主语时的主谓一致
(1)分数和百分数修饰可数或不可数名词作主语时, 谓语动词用单数形式还是复数形式取决于它们所表示的意义。试比较:
Only 60 percent of the work was done yesterday.
昨天只干了60%的活。
About 20 percent of the students are absent today.
今天大约有20%的学生缺席。
(2)由“kind(form, type, sort, portion 等)of”等修饰的主语, 其谓语形式取决于这些词的单复数而不是它们后面所跟的名词。
All kinds of difficulties have to be overcome.
必须克服各种各样的困难。
(3)“a number of(许多)”“a variety of(各种各样的)”和“a group of(一群, 一组)”修饰名词作主语时, 谓语动词用复数形式。但是“the number of(……的数目)”和“the variety of(……的种类)”修饰名词作主语时, 谓语动词用单数形式。试比较:
A number of students are from the south.
许多学生来自南方。
The number of students from the north is small.
来自北方的学生人数很少。
A variety of goods are on sale in the shop.
那个商店在出售各种各样的商品。
题组训练 用所给词的适当形式填空
[11] No one in the department but Tom and I knows (know) that the director is going to resign.
[12] With more forests being destroyed, huge quantities of good earth are (be) being washed away each year.
[13] Such poets as Shakespeare are (be) widely read, of whose works, however, some are difficult to understand.