“My son is driving my car with a learner licence and therefore no insurance. I am worried that he will get caught and go to prison. How can I stop him?”
As you are aware, it is illegal to drive without both a licence and without insurance. On top of which, not only does your son stand a chance of getting a fine and a possible jail sentence but you also run the risk of having your car seized by the police and crushed. That would soon put a stop to his driving but it would also stop your driving.
Do explain the situation to your son as it can affect the rest of his life. You can always offer him an incentive to get his licence like paying for his insurance. You can easily get Discount Car Insurance to cover him. Last but not least, do hide your keys from him to make sure he does not take your car. After all, your car is your responsibility!