There r two characters in HARRY POTTER a) Prof.Albus Dumbledore and b) Ms.Dolores Umbridge.
The two can be mentioned for the way they talk.
a) Dumbledore for his extremely polite ways.
b) Umbridge for her extremely diplomatic ways.
While one tells how how to speak, the other tells us how to be diplomatic in today's world. I don't want to be cruel and bad but, Umbridge's attitude helps us calm down when we come across unpleasant situations.