For "I don't know nuthin' about that."
a. To me, it's wrong in grammer. Instead, I will say,
1. I don't know anything about that.
2. I know nothing about that.
b. By the way, are nothing and nuthing the same?
i agree with them i think all 4 sentences are right ..
best of luck ju :-)
"I was racking my brains to think of a single reason why she has been treating me so heartlessly."
This would work for me (NES but not a teacher)
As far as your earlier post is concerned:
a) Other than in jest (as per Barb_D's post), anyone using the expression might as well say: "I don't know nuthin' about gramma' or spellin'."
b) I would regard "Nuthin', nuthing and even nothink and nuthink" as basically variations on the same English word, "nothing", as pronounced by those who haven't had access to (or profited from) a decent education.
Hope this helps
Other than in jest (as in Barb_D's case), you should avoid using the words "nuthin' " etc.