I used to could spell.

source: 
LAGS
Entry: 
657
Example: 
I used to could spell.
Modal 1: 
used to
Modal 2: 
could
Gender: 
Female
Race/Ethnicity: 
White
Age: 
82
Level of Education: 
High school and commercial college
Home Community, Town, or State: 
TX (Austin)
Location Collected: 
TX (Austin)
Year: 
1977
Relation to Addressee: 
subject to fieldworker
Medium: 
Spoken
Sentence Structure: 
1.0
Status: 
Naturalistic