[Jerry]'s grandfather [Clarence] made a pretty card for his brother, [Douglas].
('Clarence', 'Douglas')
[Jerry]'s grandfather [Clarence] made a pretty card for his brother, [Douglas].
[{('Clarence', 'grandson', 'Douglas'): [('Clarence', 'grandson', 'Jerry'), ('Jerry', 'brother', 'Douglas')]}]
['grandson', 'brother']