[John] was going out to dinner with his sister [Janet] when he received a call from his grandfather [Clarence].
('Janet', 'Clarence')
[John] was going out to dinner with his sister [Janet] when he received a call from his grandfather [Clarence].
[{('Janet', 'grandfather', 'Clarence'): [('Janet', 'brother', 'John'), ('John', 'grandfather', 'Clarence')]}]
['brother', 'grandfather']