[Clarence] bought a book for his son [Nicholas]. [Dale] asked his father [Clarence] if he could have a video game and he said okay.
('Nicholas', 'Dale')
[Clarence] bought a book for his son [Nicholas]. [Dale] asked his father [Clarence] if he could have a video game and he said okay.
[{('Nicholas', 'brother', 'Dale'): [('Nicholas', 'father', 'Clarence'), ('Clarence', 'son', 'Dale')]}]
['father', 'son']