[Nancy] taught her son [Robert] how to mow the lawn once he was old enough. [Linda] asked [Nancy], her mother, to teach her how to mow the lawn too.
('Linda', 'Robert')
[Nancy] taught her son [Robert] how to mow the lawn once he was old enough. [Linda] asked [Nancy], her mother, to teach her how to mow the lawn too.
[{('Linda', 'brother', 'Robert'): [('Linda', 'mother', 'Nancy'), ('Nancy', 'son', 'Robert')]}]
['mother', 'son']