Making Light:  Open thread 155 ::: March 29, 2011, 08:53 PM

Lee @751:

  Yes, "used to could" is definitely a Southernism; I think it's a
  contraction from "it used to be that you could"

Almost.  I'm pretty sure that "used to could" is its own construction,
based on the false analogy

  I go to the store.
  I could go to the store.
  I used to go to the store.
  I used to could go to the store.*

"It used to be that you could" is a construction to express the idea
in a grammatical way, but I don't believe it precedes "used to could".

*incorrect.