[Rosetta] went to visit her grandfather [Clarence] for his birthday. Her sister [Charlotte] could n't come as she was busy.
('Charlotte', 'Clarence')
[Rosetta] went to visit her grandfather [Clarence] for his birthday. Her sister [Charlotte] could n't come as she was busy.
[{('Charlotte', 'grandfather', 'Clarence'): [('Charlotte', 'sister', 'Rosetta'), ('Rosetta', 'grandfather', 'Clarence')]}]
['sister', 'grandfather']