[Robert] asked his father, [Wayne] to help him build a birdhouse. [Clarence] took his son [Wayne] to soccer practice.
('Clarence', 'Robert')
[Clarence] took his son [Wayne] to soccer practice. [Robert] asked his father, [Wayne] to help him build a birdhouse.
[{('Clarence', 'grandson', 'Robert'): [('Clarence', 'son', 'Wayne'), ('Wayne', 'son', 'Robert')]}]
['son', 'son']