First and foremost, you must not forget that you seldom need you to suggest what he should learn, but more often he should seek and discover what he wants to learn.What you should do is to let him have the opportunity to understand, skillfully awaken his desire to learn, and give him the means to get answers.So, you shouldn't ask him too many questions, you should be selective.And he asks you far more questions than you ask him, so you always have an advantage, and you can often ask him, "What's the use of asking this?"