人教（新课标）高中英语选修六 Unit 4 Global warming - Discovering useful structures it强调句 课件（16张ppt）

(共16张PPT)
Unit
4
Global
warming
Discovering
useful
structures
1.it
作人称代词,主要指刚提到的事物，以避免重复;
也可以指动物或婴儿.
2.it作非人称代词，有时并不指具体的东西，而泛指天气、时间、日期、距离等.
Review
the
use
of
“it”
(1)
3.用以代替指示代词this,that
4.it
作形式主语，而真正的主语是动词不定式、
动名词或从句。
5.it
作形式宾语，而真正的宾语是动词不定式、
动名词或从句。
The
use
of
“it”
(2)
The
Use
of
“it”
for
Emphasis
Compare
the
two
sentences
below.
1.Human
activity
has
caused
this
global
warming.
It
is
human
activity
that
has
caused
this
global
warming.
一.
陈述句的强调句型结构
:
For
example：
1.
Tom
ate
an
egg
at
home
this
morning
.
强调主语：
It
was
Tom
that
/
who
ate
an
egg
at
home
this
morning
.
强调宾语：
It
was
an
egg
that
Tom
ate
at
home
this
morning
.
强调时间状语：
It
was
this
morning
that
Tom
ate
an
egg
at
home.
强调地点状语：
It
was
at
home
that
Tom
ate
an
egg
this
morning
.
Tom
ate
an
egg
at
home
this
morning
.
Conclusion:
陈述句的强调句型结构
:
It
is
/was+
被强调成分
(主语/宾语/状语等)
+that/who+句子的其他成分。
（it在这种句型中本身无实际意义）
Notice：
1.
除谓语动词以外的成分都可用于强调句中;
2.
如原句时态为现在时或将来时，则be
用
is,
如原句时态为过去时,则
be用
was;
3.
当被强调部分指人时，既可以用that,也可用
who
.
二.一般疑问句的强调句型：
1.It
was
Tom
that
/
who
ate
an
egg
at
home
this
morning
.
→
Was
it
Tom
that
/
who
ate
an
egg
at
home
this
morning
?
2.It
was
at
home
that
/
who
Tom
ate
an
egg
this
morning
.
→
Was
it
at
home
that
Tom
ate
an
egg
this
morning
?
Conclusion:
Is
/
Was
+it
+被强调的部分
+
that
/
who
+
其余部分?
三.特殊疑问句的强调句型：
Conclusion:被强调部分
(通常是疑问代词或
疑问副词)
+is
/
was
+
it
+
that
/
who
+其它成分?
1.It
was
this
morning
that
Tom
ate
an
egg
at
home.
→
When
was
it
that
Tom
ate
an
egg
at
home?
2.It
was
at
home
that
Tom
ate
an
egg
this
morning
.
→Where
was
it
that
Tom
ate
an
egg
this
morning
?
not
...
until
的强调形式是：It
is
not
until
+
被强调部分
+
that
...
，主要用于强调时间状语的强调句型。
He
didn't
go
to
bed
until
his
mother
came
back.
→
It
was
not
until
his
mother
came
back
that
he
went
to
bed.
四.
not
...
until
的强调形式
Do
EX.2
(课本29页)
1.It
was
scientist
that
warned
that
greenhouse
gases
would
warm
the
earth
by
trapping
heat
erergy
in
the
atmosphere.
2.It
is
the
greenhouse
effect
that
gives
the
earth’s
surface
the
average
temperature
of
15℃.
Notice:注意区别强调句和定语从句：判断是强调句还是定语从句，可把
It
is
/
was
…that/who去掉，剩余部分在不增减任何词的情况下可以还原成一个完整的句子，那么这个句子就是强调句，否则就是定语从句。
1.It
was
at
9
o’clock
I
met
her
father
in
the
street.
2.It
was
9
o’clock
I
met
her
father
in
the
street.
A.that
B.
when
A
B
谓语的强调方式：do
/
does
/
did
+
动词原形
（1）我的确想去北京。
I
want
to
go
to
Beijing.
→
I
do
want
to
go
to
Beijing.
（2）我昨天确实买了一支新钢笔。
I
bought
a
new
pen
yesterday.
→I
did
buy
a
new
pen
yesterday.
五.
谓语的强调方式
Discussing:
What
it
was
that
caused
this
global
warming?
Review
the
use
of
“it”
and
do
EX.2
as
homework.
Preview
the
reading
passage
on
page
30.