I read some sentences where writers used nouns with has/have/had been.
What exactly does it mean?
Examples:
She has been an able administrator.
Her mother had been an American.
He has been mad at me.
What if I say?
She is an able Administrator.
Her mother was an American.
He is mad at me.
Please explain the difference.
Also when and how to use has/have/had been and is?