英语中的被动时态

被动语态表示主语是动作的承受者，在被动语态的句子中，动作的执行者，一般由介词by引起的短语来表示，如:we
often
help
them.
(主动)我们常帮助他们。they
are
often
helped
by
us.(被动)他们常被我们帮助。
1、被动语态各时态的形式是由助动词be的各时态的形式加及物动词的过去分词构成。
2、被动语态八种时态的用法例句:被动语态常用的八种时态的基本用法和主动语态各时态的
基本用法相同，只是句中的主语不是动作的执行者，而是动作的承受者，如:(1)一般现在时：now
english
is
taught
in
all
middle
schools
in
our
country.
(2)一般过去时：the
great
hall
of
the
people
was
built
in
1959.
(3)一般将来时:
when
will
the
work
be
finished?
(4)过去将来时：he
told
us
that
the
work
would
be
finished
the
next
day.
(5)现在进行时：
your
tractor
is
being
repaired
now.(6)过去进行时：the
child
was
being
examined
by
the
doctor
when
they
came
in.
(7)现在完成时：the
work
hasn’t
been
finished
yet.
(8)过去完成:the
new
plan
had
been
carried
out
before
the
second
experiment
began.
3、在下列情况下，一般使用被动语态：（1）当不知道动作执行者是谁或没有必要提到动作执行者时，如：paper
was
first
made
in
china.
（2）当强调或突出动作承受者的作用时，如：the
new
machine
was
invented
by
a
20-year-old
young
worker.
4、由主动语态转换为被动语态的几种句型：（1）将一个句子由主动语态转换为被动语态时，可按下列步骤进行：①先将主动结构的宾语改为被动结构的主语；②再将主动语态动词改为被动语态动词；③最后在被动语态之后加介词by，并将主动结构的主语放在by之后（经常被省略），构成介词短语；④由主动语态动词改为被动语态动词时，要注意被动语态动词中助动词be的各种形式变化，因为被动语态动词的不同人称和数是由助动词be不同的形式来表示的，如：trees
are
planted
every
spring.（2）如果主动语态动词后又有直接宾语，又有间接宾语，一般是将间接宾语改为被动语态句中的主语，将直接宾语保留在原处。如将直接宾语改为被动语态句中的主语，将间接宾语保留在原处时，一般要在间接宾语前加介词to或
for，如：grandma
told
me
an
interesting
story
last
night.→iwas
told
an
interesting
story
last
night./
an
interesting
story
was
told
to
me
last
night.

1.一般现在时的被动语态构成：is
/
am
/
are
+
及物动词的过去分词
Our
classroom
is
cleaned
everyday.
I
am
asked
to
study
hard.
Knives
are
used
for
cutting
things.
2.一般过去时的被动语态构成：was
/
were
+
及物动词的过去分词
A
new
shop
was
built
last
year.
Dinosaur
eggs
were
laid
long
long
ago.
3.现在完成时的被动语态构成：has
/
have
+
been
+及物动词的过去分词
This
book
has
been
translated
into
many
languages.
Many
man-made
satellites
have
been
sent
up
into
space
by
many
countries.
4.一般将来时的被动语态构成：will/shall+
be
+
及物动词的过去分词
A
new
hospital
will
be
built
in
our
city.
Many
more
trees
will
be
planted
next
year.
5.含有情态动词的被动语态构成：情态动词+
be
+
及物动词的过去分词
Young
trees
must
be
watered
often.
Your
mistakes
should
be
corrected
right
now.
The
door
may
be
locked
inside.
Your
homework
can
be
handed
in
tomorrow.
6.现在进行时的被动语态构成：am
/
is
/
are
+
being
+及物动词的过去分词
Uncle
Wang
is
mending
my
bike
now.→
My
bike
is
being
repaired
by
Tom
now.
They
are
planting
trees
over
there.
→
Trees
are
being
planted
over
there
by
them.
7.不定式的被动语态：to
+
be
+
及物动词的过去分词
There
are
two
books
to
be
read.
→
There
are
twenty
more
trees
to
be
planted.
8.过去将来时的被动语态：would
/should+
be
+
及物动词的过去分词
He
said
he
would
finish
the
work
soon.
He
said
the
work
would
be
finished
soon
by
him.