I teach him from a simple he knew, and his story enough to understand because it might make him want to learn things they never knew and a yak's new experience.
I taught him a simple story that he already knew, and he could not understand, because it might make him want to learn what he did not know and difficult to be a new experience.
I teach him from simple he knows and he can understand, because it would make him want to learn what he had never known and hard to be a new experience.