英语中主语从句怎么使用

时间：2017-11-30 16:16:17  来源：http://www.pinghe.com  作者：suki

主语指句子主要说明的人或事物，一般由名词，代词，数词，不定式，动名词，从句等充当。

(一) 词类作主语

1. 名词作主语

Tom, uncle, friend, horse, whale, insect, tree, flower, house, idea, light, honesty, British等. 如：

The hunter killed the lion. 

(The city famous for its beauty) is not far away.

2. 代词作主语

they, ours, both, everybody, that, some, who, which, few等. 如：

I am hungry.

Which is the best?

3. 数词作主语

three, first, two-thirds, percent, quarter等. 如：

(Two-thirds of the students) are boys in our school.

4. the + 形容词 / v-ed / v-ing结构作主语

(1) The young should respect the old .

(2) The dying and the wounded needed help.

(3) The wounded have been sent to hospital and the lost are being searched   for.

(二) 非谓语类作主语

1. 不定式作主语  (通常用it作形式主语)

(1) To remember to switch off the electricity is important.

(2) It is a pity not to go to the concert with you. 

(3) It took us five hours to get here.

疑问词 + to 复合结构, 如：What to do next hasn't been decided.

2. V-ing（动名词）作主语 (通常用it作形式主语)

Smoking is bad for your health. 

Buying clothes cost her a lot of money.

V-ing作主语通常表示抽象动作，而不定式结构作主语通常表示具体动作。

(1) It's no use crying over spilt milk.

(2) He realized that to go on like this was no use.

(三) 从句类作主语

1. that从句作主语 (通常用it作形式主语)

That he will succeed is certain. 

That he came late made us worried.

It  was obvious that the driver could not control his car.

[注意] that从句放于句首时，that不能省略。

2. wh-从句作主语, 注意用陈述语序, 主语从句大多数情况下视为单三, 但也有例外

 What we need is time. 

  What we need are good doctors.

  What caused the accident remains unknown.

  Who was responsible for the accident is not yet clear.

  It is not clear who was responsible for the accident.

  It is not known when he did it.

  It is not important whether you are a male or a female in the job.

3. 注意连接代词whoever, whatever, whichever等引导主语从句的含义

 Whoever comes will be welcome. (whoever = the person who)

  Whatever he did was right. (whatever = the thing that)

(四)  it用作形式主语接从句句型 

1. It + be + 形容词 + that从句

(obvious, true, natural, surprising, good, wonderful, funny, possible, likely, certain, probable)

  It is certain that she will do well in her exam.

  It is probable that he told her everything.

2. It + be + 名词词组 + that从句

(no wonder, an honour, a good thing, a pity, no surprise, etc.)     

It’s a pity that we can't go. 

It’s no surprise that our team should have won the game.

3.  It + be + P.P + that从句

(said, reported, thought, expected, decided, announced, arranged, etc.)

  It is said that Mr. Green has arrived in Beijing.

  It is reported that China has sent another man-made earth satellite into orbit.

It is v-ed that … (should)…用虚拟语气 (verb = demand, request, require, order, suggest, advise, recommend)

  It is suggested that they should begin with the third question.

4. It + seems + that从句。(seem后接that从句或as if从句)。

(look, seem, appear, happen, occur, follow, etc.)

  It seems that Alice is not coming to the party at all.

  It happened that I was out that day.

5. 几种特殊的形式主语或固定句型

It + doesn’t matter + 连接代词或连接副词引起的主语从句。如：

It doesn’t matter whether she will come or not. 

if it were not for …(若不是因为), 如：

if it were not for the fact that you are ill, I would ask you to do this right now.

It’s time that…(该…了), 如：

It's time that we set about doing our homework. = It's time that we did our homework.