[Michael]'s grandfather, [Clarence], just had a birthday. [Michael] and the rest of the family threw [Clarence] a big party. [Nicholas] went to pick up his son [Michael] from the baseball practice.
('Nicholas', 'Clarence')
[Nicholas] went to pick up his son [Michael] from the baseball practice. [Michael]'s grandfather, [Clarence], just had a birthday. [Michael] and the rest of the family threw [Clarence] a big party.
[{('Nicholas', 'father', 'Clarence'): [('Nicholas', 'son', 'Michael'), ('Michael', 'grandfather', 'Clarence')]}]
['son', 'grandfather']