Used to couldn't.
source:
LAGS
Entry:
620
Example:
Used to couldn't.
Modal 1:
used to
Modal 2:
couldn't
Gender:
Female
Race/Ethnicity:
White
Age:
70
Level of Education:
3rd grade
Home Community, Town, or State:
TX (Fort Worth)
Location Collected:
TX (Fort Worth)
Year:
1977
Relation to Addressee:
subject to fieldworker
Medium:
Spoken
Sentence Structure:
unknown
Status:
Naturalistic