[Michael] likes playing catch with his sister [Natalia], but his brother [Dennis] never wants to play.
('Natalia', 'Dennis')
[Michael] likes playing catch with his sister [Natalia], but his brother [Dennis] never wants to play.
[{('Natalia', 'brother', 'Dennis'): [('Natalia', 'brother', 'Michael'), ('Michael', 'brother', 'Dennis')]}]
['brother', 'brother']