"can't" and "can not"

[Pierce111]

Do questions given below have a different meaning (it seems to me that they should have)?

a) Can you not do it?
b) Can't you do it?

 

[bhaisahab]

Do questions given below have a different meaning (it seems to me that they should have)?

a) Can you not do it?
b) Can't you do it?

The first one is ambiguous without context.

 

[Pierce111]

So the first one can have two menings
1) that I want sombody "not to do smth"
2) exactly the same meaning as b)
Am I right?

 

[bhaisahab]

So the first one can have two menings
1) that I want sombody "not to do smth"
2) exactly the same meaning as b)
Am I right?

Yes.