An Englishman comes to Harvard.

Unable to find out the way to the library, he approaches an undergrad. The subsequent conversation is as follows-

Englishman: Excuse me. Could you kindly enlighten me where the library is at?

Undergrad: It’s Harvard. People don’t end sentences with a preposition here.

Englishman: Oh, I see. Could you kindly enlighten me where the library is at, asshole?