What will be the best car to learn the driving?

A small car is easier to handle. A used one that has a few dings so a bump into a post doesn't matter. One with bumpers that stick way out and has the original airbag. Start out in large totally empty parking lots. Sometimes an empty lot with a little snow on the ground can take the seriousness out of it for some learners. Reassure them that the brake is always there and keep your hand ready to pull the emergency brake or turn off the key for them as added reassurance. Remind them that driving is a privilege and that its always best to be predictable. Don't try teaching them on first avenue or Friday night. Perhaps make them fix any damage so they don't make a second mistake. Perhaps try at a simulator in a gamestop...