[Glen]'s grandfather [Clarence] took him and his sister [Jennifer] to the beach to play in the tide pools.
('Jennifer', 'Clarence')
[Glen]'s grandfather [Clarence] took him and his sister [Jennifer] to the beach to play in the tide pools.
[{('Jennifer', 'grandfather', 'Clarence'): [('Jennifer', 'brother', 'Glen'), ('Glen', 'grandfather', 'Clarence')]}]
['brother', 'grandfather']