before和until的区别

Question

如题所述

Answer 1

before和until的区别及用法
只要把握住两者使用时本身的含义及主句动词是终止性的，还是延续性的，肯定式，还是否定式两大点，就能容易地解决此问题。
一、在下列情况下，两者可互换用，但含义略有不同。before表示“在……之前”的意思，强调时间先后关系；而until表示“直到……才”的意思，主句是肯定句则表示主句动作的终止时间；主句是否定句则强调主句动作的起始时间。
1.主句为否定式终止性谓语动词。常见的动词是open,start,leave,arrive,finish,
stop等。例如：
(1)The
noise
of
the
street
didn't
stop
until/before
it
was
midnight.
(2)The
children
won't
come
back
until/before
it
is
dark.
(3)I
didn't
leave
the
lovely
boy
until/before
his
mother
came
home.
2.主句为肯定式、延续性谓语词，这类动词用stand,stay,talk,be,wait等。例如：
(1)He
lived
with
his
parents
until/before
he
graduated
from
school.
(2)I
will
wait
until/before
he
comes
to
my
help.
(3)I
shall
stay
here
until/before
you
come
back.
二、在下列情况下，用before不用until。
1.主句是肯定式、终止性谓语动词，只用before。例：
(1)He
fell
asleep
before
I
could
take
off
his
clothes.
(2)We
arrived
there
before
it
started
to
rain.
(3)The
holiday
came
to
the
end
before
I
knew
it.
(4)He
almost
knocked
me
down
before
he
saw
me.
2.主句谓语动词强调动词的迟缓性，只用before，常伴有时间段状语或时间段暗示。例：
(1)It
was
quite
some
time
before
he
found
the
elephant
at
all.
(2)We
had
walked
a
long
way
before
we
found
some
water.
(3)We
had
sailed
for
two
days
before
we
saw
the
land.
(4)The
fire
lasted
about
four
hours
before
the
firefighters
could
countrol
it.
(5)It
was
midnight
before
my
brother
came
home.
(6)It
was
three
months
before
they
met
again.
3.如果强调从句谓语动作未发生，就发生主句谓语动作，只用before。常译为“未及”，“不”或“不等……就”。例：
(1)We
can
leave
early
in
the
morning
before
it
gets
too
hot.
(2)I
must
write
it
down
before
I
forget
it.
(3)We
do
want
to
buy
something
now
before
prices
go
up.
4.表“与其说……倒不如”，“与其……毋宁……”只用before。例：
(1)I
would
give
up
my
job
before
I'd
agree
to
be
dismissed.
(2)He
will
die
of
hunger
before
he
will
steal.
5.在某些特定句型中用before。例如：
(1)It
was
not
long
before
the
whole
country
rose
up.
(2)It
will
probably
not
be
long
before
they
understand
each
other.
三、下列情况一般区别用until。
1.主句是持续性谓语动词时，肯定、否定都可以，但意义完全不同。肯定表动作终止，而否定表动作开始。例如：
(1)We
discussed
the
problem
until/before
he
came
back.我们一直讨论到他回来。
(2)We
didn't
discuss
the
problem
until
he
came
back.我们一直等到他回来后才讨论问题。
2.not…until句型尽管在某些情况下可与before互换用，但在强调句中一般仍用until。
例如：
(1)It
was
not
until
he
told
me
that
I
knew
it.
(2)It
was
not
until
he
finished
his
homework
that
he
went
home.
四、其他技巧
1.before只是陈述以前的事实，用until则着重后来的变化情况：This
book
was
so
interesting
that
he
read
it
for
three
hours
until
he
realized
it.
2.until引出的分句内容是真实的，而before引出的分句的内容可能是真实的，也可以是非真实的：Let's
wait
until
the
rain
stops.
Pig
will
fly
before
he'll
become
a
mathematician.