[Bernardo] asked his father, [Antonio], to help him with his math homework. [Antonio] could n't, because he was lousy at math himself. [Pedro] asked his father [Harold] if he could stay home from school because he was sick. [Harold] checked on his son [Antonio] to see if he had a fever. [Marie] is a sister of [Pedro].
('Bernardo', 'Marie')
[Bernardo] asked his father, [Antonio], to help him with his math homework. [Antonio] could n't, because he was lousy at math himself. [Pedro] asked his father [Harold] if he could stay home from school because he was sick. [Harold] checked on his son [Antonio] to see if he had a fever. [Marie] is a sister of [Pedro].
[{('Bernardo', 'aunt', 'Marie'): [('Bernardo', 'father', 'Antonio'), ('Antonio', 'sister', 'Marie')]}, {('Antonio', 'sister', 'Marie'): [('Antonio', 'brother', 'Pedro'), ('Pedro', 'sister', 'Marie')]}, {('Antonio', 'brother', 'Pedro'): [('Antonio', 'father', 'Harold'), ('Harold', 'son', 'Pedro')]}]
['father', 'father', 'son', 'sister']