could跟might用法上有什么区别？

主要区别如下：

1.

用于疑问句表示请求时，一般只用Could,且可用于各人称。如：

Could

you

help

me

explain

the

difference

between

"might"

and

"could"?

Could

I

use

your

mobile

phone

a

little

while?

上句可用May代替：May

I

use

your

mobile

phone

a

little

while?

用Might也是可以的，但不常见。

2.

could和might都可用在条件句中，表示假想的情况。表示“本来会、本来可以/能够”。例如：

If

you

tried

you

could/might

do

the

work

better.

如果你试试的话，准能把那项工作干得更好。

You

could

have

met

her

if

you

had

gone

that

way.

如果你走那条路的话，你准能遇见她。

此句中的could如改成might则表示：……，你也许能见到他。

They

could/might

have

worked

it

out

if

they

had

asked

me

for

help.

如果他们来向我求助的话，他们本能够做出来的。

He

could/might

have

give

the

answer,

but

he

refused

to.

他本来能够回答的，但他拒绝这么做。

You

were

stupid

to

go

skiing

there

—

you

could

have

broken

your

leg.

你真笨，竟会到那地方滑雪。你本来会摔断腿的。

上面的例句中用might则因其语气较轻而语意效果不甚理想。

在此场合，could和might的区别是could较might的可能性强。

3.

couldn't

be

+

比较级句型不能用might代替。如：

Their

lifestyles

couldn't

be

more

different.

他们的生活方式极为不同。

4.

could和might都可用在表示“结果”的状语从句中，同样，could语气较重些。例如：

He

expressed

his

ideas

clearly

so

that

the

average

person

might

understand.

他把他的意思清楚地表达出来，以便一般人能听明白。

5.

might

as

well表示“不妨、可以、倒不如”，此时的might是不能用could代替的。例如：

We

might

as

well

look

for

some

food

now.

现在我们不妨找些吃的东西。

I

expect

I

might

as

well

be

going.

我希望我可以走了。

We

might

as

well

have

gone

home

as

you

suggested.

我们还不如按你建议的回家去呢。