how to use them?

[billy]

question 1
:( 1. what 's the difference between them ?
2. what are the differences between them?
which one is correct?
Is "difference" countable or uncountable ?

:( question 2
any differences (or difference ) between them ? see blow.

1. forget it , forget about it
2. a little bit , a bit , a bit of , a little ( eg. a little worried, a little bit worried)
3. what would you like? how would you like?
4. I'm tired of doing... , I'm sick of doing...

[Red5]

1. what 's the difference between them ?
2. what are the differences between them?
which one is correct?

They are both correct.

[RonBee]

question 1
:( 1. what 's the difference between them ?
2. what are the differences between them?
which one is correct?
Is "difference" countable or uncountable ?

As Red said, you can say difference or differences.

:( question 2
any differences (or difference ) between them ? see blow.

1. forget it , forget about it
2. a little bit , a bit , a bit of , a little ( eg. a little worried, a little bit worried)
3. what would you like? how would you like?
4. I'm tired of doing... , I'm sick of doing...

Absent context, I would say that in each case they mean the same thing.

:)