Arundhati

“Do you remember me telling you we are practicing non-verbal spells, Potter?"
"Yes," said Harry stiffly.
"Yes, sir."
"There's no need to call me "sir" Professor."
The words had escaped him before he knew what he was saying.”
― J.K. Rowling, Harry Potter and the Half-Blood Prince

“It is impossible to live without failing at something, unless you live so cautiously that you might as well not have lived at all—in which case, you fail by default.”
― J.K. Rowling

“Is it true that you shouted at Professor Umbridge?"
"Yes."
"You called her a liar?"
"Yes."
"You told her He Who Must Not Be Named is back?"
"Yes."
"Have a biscuit, Potter.”
― J.K. Rowling, Harry Potter and the Order of the Phoenix

“Well, you're expelling us aren't you?" said Ron.
"Not today, Mr. Weasley."
Snape looked as though Christmas had been canceled.”
― J.K. Rowling, Harry Potter and the Chamber of Secrets