The spelling of the word "duke in" follows the basic rules of English phonetics. The sound of the letter 'd' is pronounced as a voiced alveolar stop, while the 'u' is pronounced as a short, central vowel. The 'k' is pronounced as an unvoiced velar stop, and the 'e' in 'in' takes a short, unstressed vowel sound. Thus, the IPA phonetic transcription of "duke in" is /djuːk ɪn/. The correct pronunciation is crucial for effective communication and understanding in both spoken and written English.