The spelling of the word "riggio" can be explained using IPA phonetic transcription. It starts with the "r" sound, which is a voiced alveolar trill. This is followed by the "ih" vowel sound, which is a short vowel pronounced with the tongue in the middle of the mouth. The next sound is a voiced velar stop, "g", and the following one is another short "ih" vowel. Finally, the word ends with the "oh" sound, which is an open-mid back rounded vowel. Overall, the spelling of "riggio" reflects the way it sounds when spoken aloud.