Harry Potter and the Prisoner of Azkaban
How we cite our quotes:
Rude and unmanageable as he almost always was, Peeves usually showed some respect toward the teachers. Everyone looked quickly at Professor Lupin to see how he would take it; to their surprise, he was still smiling.
"I'd take the gum out of the keyhole if I were you, Peeves," he said pleasantly. "Mr. Filch won't be able to get to his brooms." (7.2.8-9)
Lupin's encounter with Peeves tells us a lot about his character, oddly enough. First, we get a sense of how cool, calm, and collected Lupin is. Second, we get a peek at Lupin's very dry sense of humor. And third, we get a point re-emphasized to us: that Lupin is pretty young and that he experienced Hogwarts before as a student. He's in a rather odd position at the moment, as an ex-student now returning as a teacher.
Harry was also growing to dread the hours he spent in Professor Trelawney's stifling tower room, deciphering lopsided shapes and symbols, trying to ignore the way Professor Trelawney's enormous eyes filled with tears every time she looked at him. He couldn't like her, even though she was treated with respect bordering on reverence by many of the class. (8.1.5)
The diction used to describe Trelawney's class, such as "stifling" and "deciphering," emphasizes just how confusing and ridiculous her class is.
Nobody really liked Care of Magical Creatures, which, after the action-packed first class, had become extremely dull. Hagrid seemed to have lost his confidence. (8.1.6)
We get some great insight into teaching here: it's largely about confidence, like so many things are in life.