I used to could do it.
source:
LAGS
Entry:
677
Example:
I used to could do it.
Modal 1:
used to
Modal 2:
could
Gender:
Female
Race/Ethnicity:
Black
Age:
74
Level of Education:
College (3 years)
Home Community, Town, or State:
TN (Chattanooga)
Location Collected:
TN (Chattanooga)
Year:
1973
Relation to Addressee:
subject to fieldworker
Medium:
Spoken
Sentence Structure:
1.0
Status:
Naturalistic