ADJ of n
The 'kind' group
These adjectives indicate what quality someone showed by doing something. This use is productive: any adjective which indicates a quality can be used in this way. The adjectives listed below are the ones which are most frequently used in this way.
brave careless clever foolish generous good kind nice perceptive rude silly stupid sweet thoughtful wrong
Thank you. It's very kind of you.
That was stupid of me.