[Clarence] drove his granddaughter [Charlotte] to school. [Charlotte]'s sister [Belva] walked to school instead.
('Belva', 'Clarence')
[Clarence] drove his granddaughter [Charlotte] to school. [Charlotte]'s sister [Belva] walked to school instead.
[{('Belva', 'grandfather', 'Clarence'): [('Belva', 'sister', 'Charlotte'), ('Charlotte', 'grandfather', 'Clarence')]}]
['sister', 'grandfather']