1. Have any of you used a private driving school?
Well, I went to SEARS Driving school in Irving, Texas (DFW) --- sound like private
2. If yes, did you use an interpreter?
No and Yes -- I use one student's mom for trep since he is student same week as me. Take of advanture.... TSK on me
3. If you used a terp, who paid for the terp?
NO NO NO I borrrow his mom! 
4. If you used a terp, how did you use the terp? (That is, where did the terp sit in the car, etc.)
hard to explain -- not front seat! She sits back seat but teacher sit front seat... How ?? okay, Teacher told trep to tell us the belief so We follow it prefectly. I think its fun because I just use her as trep. sorry shame on me... yes true
5. Any other suggestions?
Any suggestions... nope 