Most Helpful Guy
I don't think children really lie with malicious intent. Every child invents some sort of fantasy, whether it be a place, a friend or whatever. It is in children's nature to invent something that isn't true.
Provided a child is never physically punished, they should be encouraged to be truthful all the time. They will soon know that when lies are discovered, the punishment will be harder. Like being grounded for two days instead of just one.1