The phonetic spelling of "HII" is [haɪ]. The word is spelled using two letters, "H" and "I", which represent the phonemes /h/ and /aɪ/ respectively. The letter "H" is pronounced as a voiceless glottal fricative sound while the letter "I" represents a diphthong, a combination of the vowel sounds /a/ and /ɪ/. The word "HII" can be pronounced as a single syllable, with stress on the diphthong [haɪ]. It is important to spell words accurately to enhance communication and comprehension.