Find and name 2 organizational patterns that made a social change in the world

The significant structural shift that happens between chapters 21 and 22 is

He had fished in the river since ten years and he was a good fisherman. he know where to found the slim sliver chilwa fish, a big beautiful mahseer and the long moustache singhara. he know where the river was deep but where it is shallow; he knew which baits to use - which fish like worms and which liked gram. edit the above

Why does the narrator come to the house of usher