The spelling of the word "Sidley" can be explained using the International Phonetic Alphabet (IPA). The first syllable, "Sid," is pronounced with the vowel sound /ɪ/ as in "sit" and the consonant sounds /s/ and /d/. The second syllable, "ley," is pronounced with the vowel sound /eɪ/ as in "day" and the consonant sound /l/. Together, the word is pronounced as "SID-lee." When in doubt about the spelling of a word, using IPA can be helpful in determining the correct pronunciation and spelling.