for / of...

Mowi sie it is rare for Sandra to behave like this

ale It was very irresponsible of you. Kiedy uzywamy of kiedy for?

of sbd - z czyjejs strony
przymiotnik, ktory przed tym stoi, wyraza opinie
How kind of you!
także: stupid, responsible, silly, nice, good itp.

Porównaj it's good for you to eat apples
it's good of you to help your neighbours