[Clarence] helped his grandson [John] cut the lawn for [John]'s mother, [Lillian].
('Lillian', 'Clarence')
[Clarence] helped his grandson [John] cut the lawn for [John]'s mother, [Lillian].
[{('Lillian', 'father', 'Clarence'): [('Lillian', 'son', 'John'), ('John', 'grandfather', 'Clarence')]}]
['son', 'grandfather']