[Marie], [Robert]'s wife sings beautifully. He is appreciative of her voice. [Lizzie] loves her grandfather [Harold] very much [Marie] took her son, [Ronald], to the movie theater for his birthday. [Ronald] and his sister [Lizzie] got their mother [Lizzie] a new computer for her birthday. She really liked it.
('Robert', 'Harold')
[Marie], [Robert]'s wife sings beautifully. He is appreciative of her voice. [Marie] took her son, [Ronald], to the movie theater for his birthday. [Ronald] and his sister [Lizzie] got their mother [Lizzie] a new computer for her birthday. She really liked it. [Lizzie] loves her grandfather [Harold] very much
[{('Robert', 'father', 'Harold'): [('Robert', 'daughter', 'Lizzie'), ('Lizzie', 'grandfather', 'Harold')]}, {('Robert', 'daughter', 'Lizzie'): [('Robert', 'wife', 'Marie'), ('Marie', 'daughter', 'Lizzie')]}, {('Marie', 'daughter', 'Lizzie'): [('Marie', 'son', 'Ronald'), ('Ronald', 'sister', 'Lizzie')]}]
['wife', 'son', 'sister', 'grandfather']