[Amy] and her son [Dennis] were taking a walk through the park when suddenly [Amy]'s father [Clarence] called.
('Dennis', 'Clarence')
[Amy] and her son [Dennis] were taking a walk through the park when suddenly [Amy]'s father [Clarence] called.
[{('Dennis', 'grandfather', 'Clarence'): [('Dennis', 'mother', 'Amy'), ('Amy', 'father', 'Clarence')]}]
['mother', 'father']