The spelling of the word "Chetwin" follows the English phonetic system. IPA phonetic transcription shows that the "ch" sound is pronounced as /tʃ/, followed by the "e" sound pronounced as /ɛ/. The "t" sound is pronounced as /t/, followed by the "w" sound pronounced as /w/ and finally the "in" sound pronounced as /ɪn/. Therefore, the correct spelling of this word is "Chetwin." It is important to pay attention to the phonetic transcription to ensure accurate pronunciation and spelling.