Once, a father came to the great Rav Shlomo Zalman Aurbach, zt"l, and complained that his son wasn't behaving properly. Rav Shlomo Zalman was able to hear from the father's tone that he constantly badgers his son without letup, and he told him, "Imagine that your son is your guest. Would you speak to him this way?" To this, the father replied. "But he isn't my guest. He is my son, and I'm obligated to be mechanech him."
When Rav Shlomo Zalman heard this, he firmly said, "I am prepared to give you a document, with my signature, attesting that you're absolved from being mechanech your son"—and he went on to write precisely such a document. The stunned father took the paper and began to exit the room, when the Gadol called him back edited the document: He erased the word "absolved" from chinuch, and in its place wrote לחנך אסור, you are prohibited from chinuch!
This is an amazing story! Rav Shlomo Zalman, the great gaon—with his incredible love and heart— understood that this father was incapable of chinuch. He wasn't engaged in chinuch... he was ceaselessly badgering and correcting his child.
Similarly, we must know that Shabbos is not a time for any of this. It is at time for singing with children, a time for joy and love with our children.
