备战2018高考英语一轮复习重难点语法讲解 名词性从句

高中英语语法——名词性从句
名词性从句相当于名词，可分别作主句的主语、表语、宾语和同位语。因此，名词性从句成分为主语从句、表语从句、宾语从句和同位从句。
（一）引导名词性从句的连接词
1、连接代词：who,
whose,
whom,
what,
which。有词义，在从句中担任成分，如主语、表语、宾语、或定语等。
2、连接副词：when,
where,
why,
how。有词义，在从句中担任成分，作状语。
3、连接词：that,
whether,
if,
as
if。that
无词义，在从句中不担任成分，有时可省略；if
(whether),
as
if虽有词义，但在从句中不担任成分。
1.
主语从句
作句子主语的从句叫主语从句。主语从句通常由从属连词that，whether，if和连接代词what，who，which，whatever，whoever以及连接副词how，when，where，why等词引导。that在句中无词义，只起连接作用；连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，在从句中充当从句的成分。例如：
What
he
wants
to
tell
us
is
not
clear.
他要跟我们说什么，还不清楚。
It
is
known
to
us
how
he
became
a
writer.
我们都知道他是如何成为一名作家的。
Where
the
English
evening
will
be
held
has
not
yet
been
announced.
英语晚会将在哪里举行，还没有宣布。
有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下：
（1）It
+
be
+
名词
+
that从句
（2）It
+
be
+
形容词
+
that从句
（3）It
+
be
+
动词的过去分词
+
that从句
（4）It
+
不及物动词
+
that
从句
另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should)
+do”，常用的句型有：
It
is
necessary
(important,
natural,
strange,
etc.)
that
…
It
is
a
pity
(a
shame,
no
wonder,
etc.)
that…
It
is
suggested
(requested,
proposed,
desired,
etc.)
that…
注意：连词that,
whether在从句中不担任句子成分，只起连接作用，不能省略。并且whether引导主语从句时不能用if代替。
Whether
there
is
life
on
the
moon
is
an
interesting
question.
月球上有没有生命是个有趣的问题。
注意：who,
which,
how,
when,
where,
why在所引导的主语从句中可担任主语，宾语，状语，不能省略。可以用形式主语it引导。
2.
宾语从句
名词句用作宾语的从句叫宾语从句。引导宾语从句的关联词与引导主语从句表语从句的关联词大致一样，在句中可以作谓语动词或介词及非谓语动词的宾语。
1.
由连接词that引导的宾语从句
由连接词that引导宾语从句时，that在句中不担任任何成分，在口语或非正式的文体中常被省去，但如从句是并列句时,第二个分句前的that不可省。例如：
He
has
told
me
that
he
will
go
to
Shanghai
tomorrow.
他已经告诉我他明天要去上海。
We
must
never
think
(that)
we
are
good
in
everything
while
others
are
good
in
nothing.
我们决不能认为自己什么都好，别人什么都不好。
注意：在demand、order、suggest、decide、insist,
desire,
request,
command等表示要求、命令、建议、决定等意义的动词后，宾语从句常用“（should）+
动词原形”。例如：
I
insist
that
she
(should)
do
her
work
alone.
我坚持要她自己工作。
The
commander
ordered
that
troops
(should)
set
off
at
once.
司令员命令部队马上出发。
2.
用who，whom,
which,
whose,
what,
when,
where,
why,
how,
whoever,
whatever,
whichever等关联词引导的宾语从句相当于特殊疑问句，应注意句子语序要用陈述语序。
例如：
I
want
to
know
what
he
has
told
you.
我想知道他告诉了你什么。
She
always
thinks
of
how
she
can
work
well.
她总是在想怎样能把工作做好。
She
will
give
whoever
needs
help
a
warm
support.
凡需要帮助的人，她都会给予热情的支持。
3.
用whether或if引导的宾语从句，其主语和谓语的顺序也不能颠倒，仍保持陈述句语序。此外，whether与if
在作“是否”的意思讲时在下列情况下一般只能用whether，不用if：
a.
引导主语从句并在句首时；b.
引导表语从句时；c
.
引导从句作介词宾语时；d.
从句后有“or
not”时；e.
后接动词不定式时。
例如：
Whether
there
is
life
on
the
moon
is
an
interesting
question.
月球上有没有生命是个有趣的问题。
Everything
depends
on
whether
we
have
enough
money.
一切要看我们是否有足够的钱。
4.
注意宾语从句中的时态呼应，当主句动词是现在时，从句根据自身的句子情况，而使用
不同时态。
例如：
he
studies
English
every
day.
（从句用一般现在时）
he
studied
English
last
term.
（从句用一般过去时）
I
know
(that)
he
will
study
English
next
year.
（从句用一般将来时）
he
has
studied
English
since
1998.
（从句用现在完成时）
当主句动词是过去时态（could,
would除外），从句则要用相应的过去时态，如一般过去时，过去进行时，过去将来时等；当从句表示的是客观真理，科学原理，自然现象，则从句仍用现在时态。
例如：The
teacher
told
us
that
Tom
had
left
us
for
America．
3.
表语从句
在句中作表语的从句叫表语从句。引导表语从句的关联词与引导主语从句的关联词大致一样，表语从句位于连系动词后，有时用as
if引导。其基本结构为：主语
+
系动词
+
that从句。例如：
The
fact
is
that
we
have
lost
the
game.
事实是我们已经输了这场比赛。
That
is
why
he
didn’t
come
to
the
meeting.
那就是他为什么不到会的原因。
It
looks
as
if
it
is
going
to
rain.
看上去天要下雨了。
需要注意的，当主语是reason时，表语从句要用that引导而不是because。例如：
The
reason
why
he
was
late
was
that
he
missed
the
train
by
one
minute
this
morning
4.
同位语从句
同位语从句说明其前面的名词的具体内容。同位语从句通常由that引导，可用于同位语从句的名词有advice、demand、doubt、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等。例如：
The
news
that
we
won
the
game
is
exciting.　
我们赢得这场比赛的消息令人激动。
I
have
no
idea
when
he
will
come
back
home.
我不知道他什么时候回来。
The
thought
came
to
him
that
Mary
had
probably
fallen
ill.
他想到可能玛丽生病了。
同位语从句和定语从句的区别：
that作为关系代词，可以引导定语从句，充当句子成分，在从句中作宾语时可以省略；
that引导同位语从句时，起连词的作用，没有实际意义，不充当句子成分，一般不能省略。
试比较下面两个例句:
I
had
no
idea
that
you
were
here．（that引导同位语从句，不能省略）
Have
you
got
the
idea（that）this
book
gives
you
of
life
in
ancient
Greece？（that引导定语从句，作宾语，可以省略）
5.疑问词 + ever和no matter + 疑问词的区别。
①
疑问词 + ever可引导名词性从句，在主从句中要充当一定的部分。如：
Whoever breaks the rule must be punished.
You can choose whatever you like in the shop.
②
疑问词 + ever还可引导让步状语从句。如：
Whoever breaks the rule, he must be punished,
Whatever you do, you must do it well.
③
no matter + 疑问词只能引导让步状语从句。如：
No matter what you do, you must do it well.
No matter who breaks the rule, he must be punished.
6.名词性从句中主句和从句的时态一致
（1）宾语从句中主句和从句的时态保持一致，但如果从句中表示提示的是客观现象，虽然主句是过去时态，从句仍用一般现在时。如：
Hello,I didn’t know you were in London. How long have you been here
The teacher told us that light travels at a very high speed.
（2）主语从句作主语相当于单数第三人称作主语，谓语动词用单数，如果由and 连接两个或两个以上的主语从句作主语时，谓语动词用复数；由两个或多个连接词引导一个主语从句，谓语动词用单数。如：
When the meeting will begin ______not been decided yet.
When they will start and where they go _______not been decided yet.
When and where the meeting will begin _______not been decided.
7.名词性从句的词序
名词性从句在句中要用陈述句语序。如：
He asked me what was the matter with me.
We’ve heard the news that we’ll move into the new house.
Whatever you say will interest us all.
8.that和what的区别
that 引导名词性从句时，在主从句中不以当任何句子成分，也没有任何含义；而what引导名词性从句时，在主从句中都要充当一定主语、宾语、表语或定语，what的意思是:“什么,
…的….” What
surprised
me
most
is
her
cheerful
expression
on
her
face.
名词性从句专项练习
1.
His
success
was
because
of
________
he
had
been
working
hard.
A.
that
B.
the
fact
which
C.
the
fact
that
D.
the
fact
2.
“Is
Mary
from
New
York
City”
“I
don't
know
_______.”
A.
from
what
city
does
she
come
from
B.
from
what
city
she
come
C.
what
city
does
she
come
from
D.
what
city
she
comes
from
3.
________
makes
mistakes
must
correct
them.
A.
What
B.
That
C.
Whoever
D.
Whatever
4.
The
reason
why
I
didn't
go
to
Shanghai
was
________
a
new
job.
A.
because
I
got
B.
because
of
getting
C.
I
got
D.
that
I
got
5.
It
worried
her
a
bit
____
her
hair
was
turning
grey.
A.
while
B.
that
C.
if
D.
for
6.
Henry
killed
the
dog.
I'll
ask
him
why
________.
A.
did
he
do
that
B.
he
did
that
C.
he
did
D.
he
has
done
so
7.
Have
you
seen
Henry
lately.
My
boss
wants
to
know
________.
A.
how
he
is
getting
along
B.
how
is
he
getting
along
C.
what
he
is
getting
along
D.
what
is
he
getting
along
8.
It
is
generally
considered
unwise
to
give
a
child
____
he
or
she
wants.
A.
however
B.
whatever
C.
whichever
D.
whenever
9.
He
asked
me
________
with
me.
A.
what
is
the
trouble
B.
what
wrong
was
C.
what
was
the
matter
D.
what
trouble
it
is
10.
I
am
sure
________
he
said
is
true.
A.
that
B.
about
that
C.
of
that
D.
that
what
11.
When
and
why
he
came
here
________
yet.
A.
is
not
known
B.
are
not
known
C.
has
not
known
D.
have
not
bee
12.
I
wonder
how
much
________.
A.
does
the
watch
cost
B.
did
the
watch
cost
C.
the
watch
costed
D.
the
watch
costs
13.
Mary
is
________
someone
might
recognize
her.
A.
afraid
of
B.
afraid
about
C.
afraid
that
D.
afraid
for
14.________
is
no
reason
for
dismissing
her.
A.
Because
she
was
a
few
minutes
late
B.
Owing
to
a
few
minutes
late
C.
The
fact
that
she
was
a
few
minutes
late
D.
Being
a
few
minutes
late
15.
They
came
to
the
conclusion
________
by
a
computer.
A.
that
not
all
things
can
be
done
B.
because
of
not
all
things
be
done
C.
being
not
all
things
can
be
done
D.
because
not
all
things
can
be
done
16.
Why
the
explosion
occurred
was
________
the
laboratory
attendant
had
been
careless.
A.
for
B.
because
C.
since
D.
that
17.
I
don't
doubt
________
he'll
come.
A.
that
B.
if
C.
what
D.
whether
18.
—“Why
did
you
go
to
the
wrong
class,
Mr.
Wang”
—“Well,
I
forget
_______
I
was
supposed
to
go
to.”
A.
which
the
room
B.
which
room
C.
what
was
the
room
D.
what
room
was
it
19.
Output
is
now
six
times
________
it
was
before
liberation.
A.
that
B.
which
C.
what
D.
of
which
20.
Mary:
Helen
is
a
mere
washer
woman,
yet
she's
now
buying
a
big
house.
Carol:
Yes.
Because
she's
always
saved
________.
A.
what
little
she
earns
B.
how
little
she
earns
C.
for
little
she
earns
D.
with
little
she
earns
21.
______
surprised
me
most
was
______
such
a
little
boy
of
seven
could
play
the
violin
so
well.
A.
That…what
B.
What…that
C.
That…which
D.
What…which
22.
We
gave
him
________
help
we
could.
A.
which
B.
what
C.
that
D.
this
23.
She
is
pleased
with
what
you
have
given
him
and
________
you
have
told
him.
A.
that
B.
which
C.
all
what
D.
all
that
24.
Excuse
me
would
you
please
tell
me
________
A.
when
the
sports
meet
is
taken
place
B.
when
is
the
sports
meet
going
to
be
held
C.
when
is
the
sports
meet
to
begin
D.
when
the
sports
meet
is
to
take
place
25.
Do
you
happen
to
know
________
A.
what
size
shoes
he
wears
B.
how
big
shoes
he
wears
C.
what
is
the
size
of
his
shoes
D.
what
number
shoes
are
his
26.
This
book
will
show
you
________
can
be
used
in
other
contexts.
A.
how
you
have
observed
B.
how
what
you
have
observed
C.
that
you
have
observed
D.
how
that
you
have
observed
27.
Where
do
you
think
________
A.
has
he
gone
B.
has
he
been
C.
he's
gone
D.
was
he
28.
Do
you
know
________
A.
how
many
populations
there
are
in
the
world
B.
how
much
population
there
is
in
the
world
C.
how
many
the
population
of
the
world
is
D.
what
the
population
of
the
world
is
29.
Would
you
go
and
see
________
outside
A.
what
to
take
place
B.
what
Tom
has
happened
C.
what
is
happening
D.
what
the
matter
had
been
30.
The
subject
of
"What
is
interesting
is
that
I
do
not
even
know
him."
is_______.
A.
what
B.
interesting
C.
What
is
interesting
D.
I
31.
________
I
think
he
is
Charles.
A.
Who
do
you
think
he
is
B.
Do
you
think
who
he
is
C.
Whom
do
you
think
he
is
D.
Do
you
think
who
he
is
32.
He
didn't
know
which
room
________.
A.
they
lived
B.
they
lived
in
C.
did
they
live
D.
did
they
live
in
33.
The
little
boy
ate
________
his
mother
gave
him.
A.
that
B.
which
C.
whatever
D.
no
matter
what
34.
The
city
is
no
longer
________.
A.
what
it
is
B.
that
it
used
to
be
C.
which
it
was
D.
what
it
used
to
be
35.
My
parents
used
________
they
had
to
get
a
new
car
for
me.
A.
which
B.
that
C.
what
D.
all
what
36.
________
we
go
swimming
every
day
________
us
a
lot
of
good.
A.
If…do
B.
That…do
C.
If…does
D.
That…does
37.
________
was
the
idea
_______
the
wife
thought
of
A.
What…that
B.
That…what
C.
How…why
D.
Why…how
38.
_______
did
he
tell
his
wife
________
he
wished
to
do
A.
That…what
B.
What…that
C.
Where…which
D.
Which…where
39.
One
of
the
men
held
the
view
________
the
book
said
was
right.
A.
what
that
B.
that
what
C.
that
which
D.
which
that
40.
I
have
no
idea
________
or
not
he
has
finished
the
work.
A.
if
B.
that
C.
whether
D.
which