➤This is about the general spelling rules for the /ɔɪ/ diphthong in English Phonics: ★ 'OY' (as in Boy, Loyal, Royal): The letters 'oy' are typically used to spell the /ɔɪ/ sound at the end of a word (boy) or at the end of a syllable (especially if the next letter is a vowel, as in loy-al and roy-al). English words usually don't end with 'i', so 'oy' is used here. ★ 'OI' (as in Boil): The letters 'oi' are generally used to spell the /ɔɪ/ sound in the middle or at the beginning of a word (boil, c