I never know," Harry called to Hagrid over the noise of the cart, "What's the difference between a stalagmite and a stalactite?"
"Stalagmite's got an 'm' in it," said Hagrid.

“With another shock of excitement, Harry saw Sirius give James the thumbs-up.Sir…”

“Daddy's gone mad, hasn't he?”

“Mr. Moony presents his compliments to Professor Snape, and begs him to keep his…”

“There is plenty to be learned even from a bad teacher: what not to do, how not …”