Quote Originally Posted by oldboy View Post
bitpicker, how is it possible to say these sentences in a different way? I just try to understand what function infinitive has in the second sentence.
It's nice to talk to you. = To talk to you is nice.
It's nice to talk to you. = To talk to you is nice. -------Yes, both are right and mean the same thing.
You are nice to talk to. = ---- That is fine.
May be You are nice for talking? ---- No, that sounds strange.

Here are some alternative ways to say the same thing, in a nice way:

It's very nice talking with you.
I am really enjoying this conversation.
Talking with you is very nice indeed.
To talk with you is so enjoyable!
It's so nice to chat with you.
This conversation is really enjoyable.
It's always nice to talk with you.


It's nice to talk to you. = To talk to you is nice.To talk to you is the subject.
But what is function of the infinitive in You are nice to talk to? Purpose?
I am not very good at grammar but I would say that the purpose of the infinitive is to specify that you are talking to that particular person, and not just talking in general. It has to be there, if you don't have it, then the sentence sounds strange.