nice(stupid, foolish, smart) of him

[keannu]

Unlike ex2, when a judgemental adjective for the subject is used, it's followed by "of" not "for". Do you know why "of" should be used? I guess it's because these adjectives are properties of a person, so "of" can mean some possessive property. Can someone explain the reason?

ex1)It was nice(stupid, foolish, smart) of him to help the old lady.
ex2)<=> It is important for us to learn English.

[keannu]

Unlike ex2, when a judgemental adjective for the subject is used, it's followed by "of" not "for". Do you know why "of" should be used? I guess it's because these adjectives are properties of a person, so "of" can mean some possessive property. Can someone explain the reason?

ex1)It was nice(stupid, foolish, smart) of him to help the old lady.
ex2)<=> It is important for us to learn English.

I guess this might be a habitual use that they don't know the reason of.

[Raymott]

Unlike ex2, when a judgemental adjective for the subject is used, it's followed by "of" not "for". Do you know why "of" should be used? I guess it's because these adjectives are properties of a person, so "of" can mean some possessive property. Can someone explain the reason?

ex1)It was nice(stupid, foolish, smart) of him to help the old lady.
ex2)<=> It is important for us to learn English.

You've already guessed a good enough reason.

[jahildebrandt]

Not a teacher.

Unlike ex2, when a judgemental adjective for the subject is used, it's followed by "of" not "for". Do you know why "of" should be used? I guess it's because these adjectives are properties of a person, so "of" can mean some possessive property. Can someone explain the reason?

ex1)It was nice(stupid, foolish, smart) of him to help the old lady.
ex2)<=> It is important for us to learn English.

Of typically refers to one party. In the first sentence, it's him; in the second, it's the one class. It's possessive in the sense that it excludes other parties and is applicable to only the one party.

Of can also be used "possessively" to indicate origin. E.g. John, C.E.O. of GM. (GM's C.E.O., John.)

[keannu]

Not a teacher.



Of typically refers to one party. In the first sentence, it's him; in the second, it's the one class. It's possessive in the sense that it excludes other parties and is applicable to only the one party.

Of can also be used "possessively" to indicate origin. E.g. John, C.E.O. of GM. (GM's C.E.O., John.)

I mean the difference between of and for in terms of the subject of to-infinitive.

[Raymott]

I mean the difference between of and for in terms of the subject of to-infinitive.

No, you were right the first time.
"Nice" is a characetistic of "him"
"Important" is a characteristic of "learning English", not of us. It's important for us; but not of us.
If someone said, "How important of you, learning English!" - it could be a sarcastic statement indicating that you think you are important because you are learning English.