[Wayne] took his son [Jeff] to soccer practice. [Clarence] took his son [Wayne] to school this morning because he missed the bus.
('Clarence', 'Jeff')
[Clarence] took his son [Wayne] to school this morning because he missed the bus. [Wayne] took his son [Jeff] to soccer practice.
[{('Clarence', 'grandson', 'Jeff'): [('Clarence', 'son', 'Wayne'), ('Wayne', 'son', 'Jeff')]}]
['son', 'son']