Book3語法專題：名詞性從句

1、名詞性從句中連接詞的運(yùn)用

★（1）that的用法。

①主語從句、表語從句、同位語從句中用that但不能省略。如：

That they are good at English is known to us all.

The problem
is
that we don’t have enough money.

She expressed
the hope that they would come to Chinaone day.

②賓語從句中的連接詞that有時(shí)可省有時(shí)又不可省，在以下幾種情況中that不能省略：（A）當(dāng)that從句和主句謂語動(dòng)詞之間有插入詞語或者從句主語之間有插入語時(shí)，that不可省略；（B）當(dāng)that 從句與另一名詞性從句并列作賓語時(shí)，that不能省；（C）當(dāng)that作介詞賓語時(shí)，that不可省掉。如：

He judged that,
because he was a child, he did not understand wine.

Everyone knew
what happened and that she was worried.

The reason
lies in that she works harder than the others do.

③that從句作主語和賓語時(shí)，可以用it 來替換成以下幾種結(jié)構(gòu)表達(dá)。

(A) It is clear/certain/likely/true/surprising
that…

(B) It is a pity/shame/good idea/no wonder that
...

(C) It is said/reported/
believed/known/thought/suggested that …

(D) It seems/happens that。如：

It happened that
I went out last night.

It is said that
China
will win in the World Cup.

④that和what的區(qū)別。

that 引導(dǎo)名詞性從句時(shí)，在主從句中不以當(dāng)任何句子成分，也沒有任何含義；而what引導(dǎo)名詞性從句時(shí)，在主從句中都要充當(dāng)一定的句子成分，what可以分解成定語從句中的先行詞 + 關(guān)系代詞即常說的先行詞 + that。如：

It’s shame that
he has made such a mistake. Do what he says.

⑤ 同位語從句與定語從句中that的區(qū)別。

同位語從句中的連詞that只起連接作用，在從句中不擔(dān)當(dāng)任何句子成分；而定語從句中的關(guān)系代詞that在句中做賓語或主語，賓語與先行詞有修飾關(guān)系。如果句子是同位語從句，就應(yīng)用連詞that而不能用which.同位語從句一般放在表具體含義的名詞后解釋名詞的含義或內(nèi)容，如以下名詞：news、fact、suggestion、truth、plan、belief、doubt、possibility、idea等，而定語從句只是對先行詞的限定和修飾。如：

They
expressed the hope that they would come to visitChinaagain. (同位語從句)

The hope she
expressed is that they would come to visitChinaagain.（定語從句）

★（2）whether和if的用法。

①whether和if在賓語從句中可以互換，但是作介詞賓語時(shí)連接詞一般用whether。如：

②后面直接跟or not 時(shí)用whether。如：

③主語從句表語從句中只能用whether。如：

④whether可以引導(dǎo)同位語從句，用以說明前面的名詞的內(nèi)容，if不能。如：

⑤whether常與or連用表示一種選擇，if不能這樣用；whether也可與動(dòng)詞不定式連用但if不能。如：

⑥間接引語位于句首時(shí)或者是間接引語提前時(shí)用whether不用if。如：

⑦whether可引導(dǎo)一個(gè)讓步狀語從句表示“不管”、“無論”，而if不能。如：

Practice:選用if和whether填空

1.I didn’t know __________or not he had arrived inWuhan.

2._________the meeting will be put off has not been decided yet.

3.The question is _______________they have so much
money.

4.We ought to discuss carefully the question_____________ we can do
it or not.

5.The question of ____________they are male or female
is not important.

6.I have not decided_____________ to go or not.

7.Thank you, but ____________ _I’ll be free I’m not
sure at the moment.

8.It all depends on ______________ they will come back.

9._________________ he comes or not,
we will begin our party on time.

★（3）疑問詞 + ever和no matter + 疑問詞的區(qū)別。

①疑問詞 + ever可引導(dǎo)名詞性從句，在主從句中要充當(dāng)一定的部分。如：

Whoever breaks the rule must be punished. (在主句中做______語)

You can
choose whatever you like in the shop. (在主句中做______語)

②疑問詞 + ever還可引導(dǎo)讓步狀語從句。如：

Whoever breaks the rule, he must be punished,

Whatever you do, you must do it well.

③no matter + 疑問詞只能引導(dǎo)讓步狀語從句。如：

No matter what you do, you must do it well.

No matter who breaks the rule, he must be punished.

★（4）when和where引導(dǎo)的同位語從句與定語從句的區(qū)別。

when 和where前面的名詞若是表示時(shí)間、地點(diǎn)的名詞，則when和where引導(dǎo)的是定語從句，否則則為同位語從句。如：

They put
forward the question where they could get the money.

This is the
place where the accident happened.

2、名詞性從句中主句和從句的時(shí)態(tài)一致

（1）賓語從句中主句和從句的時(shí)態(tài)保持一致，但如果從句中表示提示的是客觀現(xiàn)象，雖然主句是過去時(shí)態(tài)，從句仍用一般現(xiàn)在時(shí)。如：

Hello, I
didn’t know you were inLondon.
How long have you been here?

The teacher
told us that light travels at a very high speed.

（2）主語從句作主語相當(dāng)于單數(shù)第三人稱作主語，謂語動(dòng)詞用單數(shù)，如果由and 連接兩個(gè)或兩個(gè)以上的主語從句作主語時(shí)，謂語動(dòng)詞用復(fù)數(shù)；由兩個(gè)或多個(gè)連接詞引導(dǎo)一個(gè)主語從句，謂語動(dòng)詞用單數(shù)。如：

When the
meeting will begin has not been decided yet.

When they
will start and where they go have not been decided yet.

When and
where the meeting will begin has not been decided.

3、名詞性從句的詞序：名詞性從句在句中要用陳述句語序。如：

He asked me ____________________________(我怎么了\發(fā)生什么事了).

We’ve heard
the news that we’ll move into the new house.

______________________________(無論你說什么) will interest us all.