The spelling of the word "NASSLEO" can be a bit confusing at first glance. However, using the International Phonetic Alphabet (IPA), we can break down its pronunciation: /næsliːoʊ/. This reveals that the word is comprised of two syllables: "nas" and "sleo." The "s" sound is repeated twice, once in each syllable, making the spelling a little tricky. With consistent practice, however, the pronunciation and spelling of "NASSLEO" can become second nature.