How we cite our quotes: All quotations are from Harry Potter and the Sorcerer's Stone.
Quote #1
VERNON: I'm warning you now, boy. Any funny business, any at all, and you won't have any meals for a week. Get in.
By "funny business," Vernon means Harry's ability to practice magic. He eagerly separates him into a different class than the Dursleys, even though Harry's more powerful than them in so many ways.
Quote #2
HAGRID: Oh, um, I'd appreciate if you didn't tell anyone at Hogwarts about that. Strictly speaking, I'm not allowed to do magic.
Another sign of class distinction, thrown out so subtly we almost miss it. Hagrid's a servant at Hogwarts, not a student. Therefore, no magic for him.
Quote #3
HAGRID: They're goblins, Harry. Clever as they come, goblins, but not the most friendly of beasts. Best stick close to me.
Social divisions aren't limited to human beings in this world. Goblins clearly hold a very structured place in the world…and are subjected to some quiet prejudices for it.