[Glen] asked his brother [Dennis] to help him fix his car and he said he would after he got off work. [Dennis] always enjoyed playing with his sister, [Mary], when they were growing up.
('Glen', 'Mary')
[Glen] asked his brother [Dennis] to help him fix his car and he said he would after he got off work. [Dennis] always enjoyed playing with his sister, [Mary], when they were growing up.
[{('Glen', 'sister', 'Mary'): [('Glen', 'brother', 'Dennis'), ('Dennis', 'sister', 'Mary')]}]
['brother', 'sister']