-
“情态动词
+have
done
”
表推测一览表
情态动词
+ have done
must have done
can
’
t have done
could have done
用法
一定已经做了
不可能已经做了
例句
They must have
finished their work.
They
can
’
t have finished their
work
可能已经做了或本来可
You could
have used my computer because I
didn
’
t use it.
能做但未做
may have
done
might have done
也许已经做了
They may
have finished their work.
也许已经做了或本来可
You might have
used my computer because I
didn
’
t use it.
以做但未做
Should/ought to have done
need not have done
would
rather have done
would like to have
done
had better have done
本来该做但未做
本来不必做但做了
过去宁愿做但未做
过去想做但未做
当时最好做了某事
You
Should have studied hard.
You need not
have gone out.
I would rather not have
gone there.
I would like to have seen
the film.
You
’
t
better have gone there.
“情态动词
+be
doing
”
表推测一览表
情态动词
+ be doing
must be doing
can
’
t be doing
May/might be doing
用法
一定正在做
不可能正在做
也许正在做
例句
They must be
watching TV now.
They
can
’
t be watching TV now.
They may be watching TV now.
口诀：
“情动”加上
have
done,
推测事情已经干；
“情动”加上
be
doing,
推测事情在进行；
条件
状语从句中的虚拟语气：条件句分为真实条件句和虚拟条件句两种，真实条件句用陈述语气，
虚拟条件句用虚拟语气。
（虚拟条件句是虚拟语气的重点）
虚拟条件句关键是要熟练掌握以下三大公式：
三个相反
与现在事实相反
与过去事实相反
与将来事实相反
从句
主句
If sb
did/were
…
If sb
had
done
…
If
sb
did/were
…
If sb
were to
do
…
If sb
should do
…
Sb
would/should/could/might
do
…
Sb
would/should/could/might have done/have
been
…
Sb
would/should/could/might
do
…
1
、宾语从句中的虚拟语气：有三种情况。
一是在动词
insist
(
坚持<
/p>
)
，
order
（
命令）
，
command
(
命令
)
，
suggest
（建议）
，
advise
（建议）
。
Recomm
end
（建议，推荐）
，
requir
e
（要求）
,request
（请求）
，
demand
（要求）
，
desire
（要求，
愿
望）
，
等动词后面的宾语从句中一般用虚拟语气，其结构为
“主语
+should+
动词原形”
，
其中
should
可以省略。
把以上
10
个动词简称为
：
一个“坚持”
，两个“命令”
，三个“建议”
，四个“要求”
。
二是动词
wish
之后接宾语从句一定要用虚拟语气。
从句的时态是：
1
、与过去事实相反用
had
done/had been,
2
、与现在事实相反用
did
或
were,
3
、与将来事实相反用
“
would/might/could/should+
动词原形”
。
注意：
wish<
/p>
在简单句中并非表示的是虚拟语气，如：
wish you
success.
祝你成功。
三是在
would rather
的宾
语从句中，
也要使用虚拟语气，
其从句中谓语动词的时态用一般
过去
时。如：
I would rather you
didn
’
t hear what I said.
我宁愿你没有听到我说的话。
2
、主语从句中的虚拟语气
少数
“
it is+
< br>形容词
+that+
主语
+sh
ould+
动词原形”
，
其中
should
同样可以省略。常见形容
词有：<
/p>
important,necessary,strange,unusual,curi
ous,remarkable,surprising,desirable,natural
等。
3
、定语从句中的虚拟语气
“
it is(high/about) time that
+
主语
+
动词的过去式，
或者是
“
should+
动
词原形”
。
Time
是先行词
，
that
是引导词
，
其意思是“早该做什么事了”
如：
1
、
It
is high time that you went to school.=it is high
time that you should go to
school.
你该上学了。
2
、
It is about
time that you picked up your daughter at school.=
It is about time that you
should pick
up your daughter at
school.
你该去学校接你女儿了。
熟练掌握强调句型：句型结构是：
it is/was+
被强调部分
+that/who+
句子原有部
分
。在强调
句型中，
强调人时，
一般用
who,
也可用
that,
但强调时间，
地点等时只能用
that,
不能用
when,where
< br>等。
1
、
2
、
3
、
4
、
强调主语
强调地点状语
强调时间状语
强调宾语。
not
…
until
…
的三大句型：
例：妈妈回家之后我才睡觉。
正常
I
did not go to bed until my mother come back home.
强调
It
was not until my mother came back home that I went
to bed.
倒装
Not until my mother came back home did
I go to bed.
怎样识别
not
…
until
…
是强调句还是
倒装句呢？很简单，如果否定词
not
在句首，就是倒装
句，如果
it
在句首，就是强调句。
it
的
10
大句型
1
、
It was for the
first time that I wrote to a foreign pen friend.
这确实是我第一次给一个外
国笔友写信。
这是强调句型。还原为：
I
wrote to a foreign pen friend for the first time.
2
、
It is the first
time that I have written to a foreign pen
friend.
这是我第一次给一个外国
笔友写信
<
/p>
这是定语从句，
that
之后的时态要用
现在完成时态。
3
、
It was eight
when the class
began.
8
点钟开始上课。
这是时间状语从句，强调句型：
It
was at eight that the class began.
4
、
It is possible
that I will enter this key
university.
我上这所重点大学是可能的。
这是主语从句。
It
是形式主语。
that I will enter this key university
是真正主语。还原成：
That I will enter this key university
is possible.
5
、
It
is/has been three years since he got
married.
他结婚（成家）已经三年了。
It is/has been some time since sb did
(
短暂性动词
)
s
th.
意为“自从某人干某事已经有多长时
间”例如：
It is/has been three years
since he worked
here.
他不在这儿工作已经三年了。
6
、
It will be one
year before she finishes middle
school.
再有一年时间她就中学毕业了。
It is/was/ will be some time before
…
意为“过多长时间后再干什么”
。
7
、
It is
high time we went to
school.
我们上学的时间到了。
这时定语从句，在
It is
（
high
）
time that
…
句型中
，
that
之后谓语动词的时态要用一般过去
时或
“
should+
动词原形”
，
属于虚拟语气。
8
、
It is said that
a new factory will be built nearby my hometown.
据说一家新工厂将见在
我家乡附近。
这时主语从句。
it is+
过去分词
+that
…
..
。类似的句型还有：
It is reported
that
…
/ It is known
that
…
/ It is
thought that
…
/ It
is suggested that
…
/ It is
believed that
…
/ It is hoped
that
…
等。
9
、
It looks as if
it is going to snow.
看起来要下雪了。
这时表语从句，类似的句型还有：
It seems to
sb that
…
/ It (so)happened
that
…
/ It appears
to sb that(=as
if
)…
等。
10
、
It is
necessary that we should master a foreign
language.
我们掌握一门外语是必需的。
这是主语从句，在“
It
is+
少数形容词
+that sb should do <
/p>
…”
这种句型中，
it
< br>同样是形式主
语，
that
之后
从句的谓语动词是
“
should+
动
词原形”
，其中
should
可以省略
。这样的形
容词有
necessary/important/
unusual/strange/natural
等
。
情态动词
+have
done
表推测
一、
must have done
一定已经做了。