[Not quite at ease, half shy, half assertive] Eric Act 1, immediately described as an uncomfortable member of the family
"Why shouldn't they try for higher wages?" Eric Act 1, socially aware, first once to pick up the unfairness of the lower class, contradicts his father - against social norms
"I don't give a damn" Eric Act 3, openly expresses his disrespect for his father
"I don't even remember - that's the hellish thing" Eric Act 3? religious connotations showing audience his disgraceful actions
"I don't even remember" either from drinking or can't bring himself to describe his actions and feelings
"You're not the kind of father a chap could go to when he's in trouble" Eric Act 3, shows Birlings are inadequate parents and Eric's hatred towards Arthur. Makes audience sympathise for him.
"We helped to kill her." Eric Act 3, admitting to his mistakes, maturing,
"You're beginning to pretend now that nothing's really happened at all. And I can't see it like that." Eric A3.