[Clarence] is taking is son [Nicholas] out for a weekend camping trip. [Nicholas]'s son [Milton] is sick and can not go.
('Milton', 'Clarence')
[Clarence] is taking is son [Nicholas] out for a weekend camping trip. [Nicholas]'s son [Milton] is sick and can not go.
[{('Milton', 'grandfather', 'Clarence'): [('Milton', 'father', 'Nicholas'), ('Nicholas', 'father', 'Clarence')]}]
['father', 'father']