posted by John .
A: How do you like the present, Mom?
B: Oh, it is great. It's so kind of you.
In the short dialogue above, what is the full form of 'It's so kind of you.'?
It is so kind of you to give me the present. --- Is this the full form for that?
What is term of the English term for "It"?
"It" is a pronoun, but in this type of sentence, it's more of an idiom since there is no one noun to which it refers.
The full form that you wrote is fine.