[John] asked his father, [George] to help him build a birdhouse. [Nicholas] took his nephew [John] fishing for his birthday. They had a great time.
('George', 'Nicholas')
[John] asked his father, [George] to help him build a birdhouse. [Nicholas] took his nephew [John] fishing for his birthday. They had a great time.
[{('George', 'brother', 'Nicholas'): [('George', 'son', 'John'), ('John', 'uncle', 'Nicholas')]}]
['son', 'uncle']