Actually we cant' find any adults who never lie now. We do not make this point to justify lying, but to show that children who lie are not defective or immoral. We need to deal with the reasons children lie before we can help them give up their need to lie. Often lying is a sign of low self-esteem. People think they need to make themselves look better because they don't know they are good enough as they are.
Suggestions Stop asking set-up questions that invite lying.
A set-up question is one to which you already know the answer. Focus on solutions to problems instead of blame. Be honest yourself. Most of us don't tell the truth when we are feeling trapped, scared, or threatened in some way. Later I'll be available if you would like to share with me what is going on for you.