The word "thyia" is not a common word, but its spelling follows the phonetic rules of English. In IPA (International Phonetic Alphabet) transcription, it is pronounced as /ˈθaɪə/. The first syllable is pronounced with a voiceless dental fricative "th," followed by a diphthong of "aɪ" and a reduced schwa sound "ə." The main challenge in spelling this word lies in the first syllable, which features the unique "th" sound. Nonetheless, once you master the phonetic symbols, you can spell out any word with ease.