The correct spelling of the phrase "doest over again" is actually "does it over again." The reason for the unusual spelling is that it is phonetically transcribed using the International Phonetic Alphabet (IPA). In IPA, the "t" sound in "doest" is actually a representation of the voiced "th" sound, while the "o" represents the "uh" sound. Therefore, the correct spelling using regular English orthography is "does it over again."