大学英语(三)middot问题答疑材料

大学英语（三）·问题答疑材料

马静

一、定冠词与不定冠词

冠词是虚词，本身不能单独使用，也没有词义，它用在名词的前面，帮助指明名词的含义。英语中的冠词有三种，一种是定冠词（the Definite Article），另一种是不定冠词（the Indefinite Article），还有一种是零冠词（Zero Article）。

（一）不定冠词a (an)与数词one 同源，是"一个"的意思。a用于辅音音素前，一般读作[e]，而an则用于元音音素前，一般读做[en]。

1) 表示"一个"，意为one；指某人或某物，意为a certain。

A Mr. Ling is waiting for you.

2) 代表一类人或物

A knife is a tool for cutting with.

Mr. Smith is an engineer.

定冠词the与指示代词this，that同源，有"那（这）个"的意思，但较弱，可以和一个名词连用，来表示某个或某些特定的人或东西。

（二）定冠词的用法:

1）特指双方都明白的人或物：

Take the medicine.把药吃了。

2）上文提到过的人或事：

He bought a house.I've been to the house.

他买了幢房子。我去过那幢房子。

3）指世上独一物二的事物：

the sun，the sky，the moon，the earth

4）单数名词连用表示一类事物，如：the dollar 美元;

the fox 狐狸；或与形容词或分词连用，表示一类人：the rich 富人; the living 生者。

5）用在序数词和形容词最高级，及形容词only，very，same等前面：

Where do you live?I live on the second floor.你住在哪？我住在二层。

That's the very thing I've been looking for.那正是我要找的东西。

6）与复数名词连用，指整个群体：

They are the teachers of this school.指全体教师)

They are teachers of this school.(指部分教师)

7）表示所有，相当于物主代词，用在表示身体部位的名词前：

She caught me by the arm..她抓住了我的手臂。

8）用在某些由普通名词构成的国家名称、机关团体、阶级、等专有名词前：

the People's Republic of China中华人民共和国

the United States美国

9）用在表示乐器的名词之前：She plays the piano.她会弹钢琴。

10) 用在姓氏的复数名词之前，表示一家人：

the Greens格林一家人(或格林夫妇)

11) 用在惯用语中：

in the day, in the morning (afternoon，evening),the day after tomorrow the day before yesterday,the next morning等等。二、虚拟语气的用法：

（一）: 最基本的虚拟语气句型:

1. 虚拟现在时表示与现在事实相反的假设，其if 从句的谓语形式用动词的过去式(be 一般用were)，主句用would/ should/ could/ might +动词原形。If places were alike, there would be little need for geographers.如果各个地方都一样，就不需要地理学家了。

2. 虚拟过去时是表示与过去事实相反的假设，if 从句的谓语形式用过去完成时即had＋过去分词，主句用would / should / could / might + have +过去分词。If he had known your address yesterday,he would have telephoned you.

3. 虚拟将来时是表示对将来实现的可能性很小的或不确定的假设。If从句的谓语形式用一般过去式或用were to / should +动词原形，主句用would / should/could/ might +动词原形。If he were to leave today, he would get there by Friday

4. 省略if 采用倒装语序的条件句。有时可以把含有助动词、情态动词、be或have的虚拟条件句中的连词if省去，而将

had , should, were 等词提到主语之前，即用倒装结构。If he had worked harder, he would have got through the exams.==>Had he worked harder, he would have got through the exams.If he were to leave today, he would get there by Friday.==>Were he to leave today, he would get there by Friday.If I were in your place, I wouldn‟t do that.==>Were I in your place, I wouldn‟t do that.

5. 有时虚拟条件句并没用if 从句表示出来，而是用介词短语(otherwise, or, without, but for)、上下文或其它方式来表示。如：We didn't know his telephone number; otherwise we would have telephoned him. Without you help, I wouldn‟t h ave achieved so much. But for （“要不是......”的意思）your help, I would not have succeeded.

（二）: 虚拟语气在从句中用should的情况:

1. 在表示建议,要求,命令,想法的动词后的从句里, 用should + 动词原形, should 可以省略. 如advise, agree, command, decide, demand, determine, grant, indicate, insist, order, prefer, propose, request, require, stipulate, suggest, urge, vote.常考到的是: suggest, advise, demand, require, propose, insist, order, request.

His doctor suggested that he (should) take short leave of absence.

The author proposed that TV (should) be turned off at least one hour every day.

2. 在表示建议,要求,命令,想法的名词后的从句里, 用should + 动词原形, should可以省略. 如advice, decision, agreement, command, decree, demand, determination, indication, insistence, order, preference, proposal, request, requirement, stipulation etc.

I t was Bill‟s suggestion that everyone (should) have a map.

His suggestion was that everyone (should) have a map.

He gave us a suggestion that everyone (should) have a map.

3. 在It is/was +形容词后的that 从句中用should的结构, should 可以省略. 这类形容词常见的有: advisable, anxious, compulsory, crucial, desirable, eager, essential, fitting, imperative(绝对必要), impossible, improper, important, natural, necessary, obligatory, possible, preferable, probable, recommended, urgent, vital etc.

It…s natural that she (should) do so.

It is essential that we (should) tell her the news.

4. 在lest 和for fear that(以免),in case(以防)从句中用should, should 可以省略.

She walked quietly lest she (should) wake up her roommates.

Have your gun ready in case we should need it.

（三）: wish 后的that 从句中:

1. 表示现在或将来的愿望,从句中过去式.

I wish I knew his address.

I wish I were young.

2. 表示过去没有实现或不可能实现的愿望, 从句用过去完成式或would, could, might + have + 过去分词.

I wish you had written to him.

I wish I could have slept longer this morning, but I had to get up and come to class.

3. 如果将wish改成wished, 其后that 从句中动词的形式不变.

4. 如果that 从句中用would , 一般表示对现状不满或希望未来有所改变或请求

I wish he would answer my letter.

I wish prices would come down.

I wish you would help me.

I wish you would stop asking silly questions.

（四）: 在It‟s about/ high/ fir st(second, third etc)time 后的that 从句中,用过去式.表示“该是做什么的时候了”

It is about time you were in bed.

It is high time we left.

It is the first time I came here.

（五）: 在would rather, would sooner, would just as soon 后的that从句中,用过去式或过去完成式,表示“宁愿做什么”

I would rather he came tomorrow than today.

John would rather that she had not gone to the party yesterday evening.

（六）: 在if only（“如果....就好了”的意思）感叹句中,谓语动词与wish宾语从句的虚拟形式相同.

If only he didn‟t drive so fast! (现在)

If only she had asked someone‟s advice.(过去)

If only the rain would stop.(将来)

（七）: 在as if / as though 从句中,表示和现在事实相反或对现在情况有所怀疑,用过去式;表示过去想象中的动作或情况, 用过去完成式

He speaks as if he were on the spot.

She spoke to me as if I were deaf.

This device operated as though it had been repaired.