[Nancy] bought some shoes for her father [Clarence]. [Clarence] took his son [George] to soccer practice.
('Nancy', 'George')
[Nancy] bought some shoes for her father [Clarence]. [Clarence] took his son [George] to soccer practice.
[{('Nancy', 'brother', 'George'): [('Nancy', 'father', 'Clarence'), ('Clarence', 'son', 'George')]}]
['father', 'son']