[Clarence]'s grandson, [John], was busy planning a birthday dinner for his brother, [Douglas].
('Clarence', 'Douglas')
[Clarence]'s grandson, [John], was busy planning a birthday dinner for his brother, [Douglas].
[{('Clarence', 'grandson', 'Douglas'): [('Clarence', 'grandson', 'John'), ('John', 'brother', 'Douglas')]}]
['grandson', 'brother']