"Didn't this used to be..." is WRONG. "Did" is past tense, so "used" need not be. "Didn't this use to be..." is the right way to write that. Hell, i even found this written wrong in American Gods.
"Didn't this used to be..." is WRONG. "Did" is past tense, so "used" need not be. "Didn't this use to be..." is the right way to write that. Hell, i even found this written wrong in American Gods.