The spelling of the word "Postero" can be explained using IPA phonetic transcription. The first syllable "pos-" is pronounced as /poʊs/ with a long O sound followed by an S sound. The second syllable "-te-" is pronounced as /teɪ/ with a long A sound and a silent E. The final syllable "-ro" is pronounced as /roʊ/ with a long O sound followed by a silent R. Altogether, the word "postero" is pronounced as /poʊs-teɪ-roʊ/. It is important to remember the correct spelling and pronunciation of words for effective communication.