The word "santillo" is a bit tricky to spell because of its unique pronunciation. In IPA phonetic transcription, it is spelled /sænˈtɪloʊ/. The "s" and "a" sounds are straightforward, but the "n" and "t" sounds can be easily mixed up. The word ends with the "iloh" sound, which is spelled with "i" followed by "lo." Overall, "santillo" shouldn't be too difficult to spell once you become familiar with its pronunciation.