Complex sentence: One day, his father finds a broken automaton, a mechanical man designed to write with a pen, at the museum, and Hugo and he try to repair it, his father documenting the automaton in a notebook.
Split into simpler sentences: One day, his father finds a broken automaton-a mechanical man designed to write with a pen-at the museum. He and Hugo try to repair it, with Hugo's father documenting the automaton in a notebook.