The spelling of "study at earthly" can be confusing because of the silent "e" at the end of "earthly." This silent "e" indicates that the vowel in the previous syllable is pronounced as a long "e" sound. Therefore, the correct IPA phonetic transcription for "earthly" is /ˈɜrθli/. It is important to pay attention to silent letters in English words as they can change the pronunciation and meaning of a word. In this case, correctly spelling and pronouncing "earthly" ensures effective communication in academic and professional contexts.