They used to would walk.

source: 
LAGS
Entry: 
725
Example: 
They used to would walk.
Modal 1: 
used to
Modal 2: 
would
Gender: 
Male
Race/Ethnicity: 
White
Age: 
49
Level of Education: 
10th grade
Home Community, Town, or State: 
AR (Leslie/Maple Grove area)
Location Collected: 
AR (Baker)
Year: 
1974
Relation to Addressee: 
subject to fieldworker
Medium: 
Spoken
Sentence Structure: 
1.0
Status: 
Naturalistic