[John] likes to go fishing with his sister. Her name is [Janet]. [April]'s sister, [Janet], recently started acting.
('John', 'April')
[John] likes to go fishing with his sister. Her name is [Janet]. [April]'s sister, [Janet], recently started acting.
[{('John', 'sister', 'April'): [('John', 'sister', 'Janet'), ('Janet', 'sister', 'April')]}]
['sister', 'sister']