[Nicholas] bought a present for his mother [Ashley]. [Nicholas] and his son [Dennis] went to the park to look for different kinds of birds.
('Dennis', 'Ashley')
[Nicholas] and his son [Dennis] went to the park to look for different kinds of birds. [Nicholas] bought a present for his mother [Ashley].
[{('Dennis', 'grandmother', 'Ashley'): [('Dennis', 'father', 'Nicholas'), ('Nicholas', 'mother', 'Ashley')]}]
['father', 'mother']