while的用法

while

一段时间；当……时（和……同时）；却

（1）I”ll

be

back

for

a

while

（2）He

fell

asleep

while

doing

homework.

（3）John

was

dressed

in

brown

while

Mary

was

dressed

in

blue

连词while大致有以下四种用法:

1.引导时间状语从句,意为"当……的时候和……同时",此时的主从句谓语动作同时发生,从句谓语通常是延续性动词。如:

Mary

watched

TV

while

she

ate

her

supper.玛丽边吃饭边看电视。

While

she

was

listening

to

the

radio,

she

fell

asleep.她听着收音机睡着了。

while引导从句时,如主从句的主语一致,且从句谓语又含有be,则从句主语和be可省略。while后可直接跟现在分词、名词、形容词或介词短语。如:

We

are

teachers

while

(we

are)

serving

as

students.我们边当老师边当学生。

While

(he

was)

yet

a

youth,

he

gained

many

prizes.他年轻时就曾多次获奖。

He

caught

a

cold

while(he

was)

on

vacation.他度假时患了感冒。

2.表示对比或转折,意为"而然而"。此时,while一般位于句中。如:

Some

people

waste

food

while

others

haven't

enough.有些人浪费粮食,然而有些人却吃不饱。

You

like

sports,

while

I

prefer

music.你喜欢体育,而我更喜欢音乐。

3.表示让步,通常位于句首,意为"尽管虽然"。如:

While

I

agree

with

your

reasons,

I

can't

allow

it.尽管我同意你的理由,但我不能允许这样做。

While

he

loves

his

students,

he

is

very

strict

with

them.虽然他爱他的学生,可是他对学生们很严格。

While

(he

was)

respected,

he

is

not

liked.他虽受人尊敬,但并不被人喜欢。

4.表示条件,意为"只要",其意思和用法相当于as

long

as。while可位于句首,也可位于句中。如:

You

don't

have

to

worry

while

we

are

here.只要我们在,你就别着急。

There

will

be

life

while

there

is

water

and

air.只要有空气和水,就有生命。

While

there

is

life,

there

is

hope.留得生命在,不怕没希望。