[Robert] and his brother [Adan] played at jacks. [Adan]'s father, [John], bought him some ice cream.
('Robert', 'John')
[Robert] and his brother [Adan] played at jacks. [Adan]'s father, [John], bought him some ice cream.
[{('Robert', 'father', 'John'): [('Robert', 'brother', 'Adan'), ('Adan', 'father', 'John')]}]