The phrase "hast on the carpet" is an archaic way of saying that someone has made a mistake or caused trouble. The word "hast" is an old-fashioned form of the verb "have", used in the second person singular (you). It is pronounced with a short "a" sound, as in "hat", and the "s" is pronounced like a "z". The IPA phonetic transcription for "hast" is /hæst/. While this usage of the word is no longer common, it can still be found in literature from earlier periods.