The spelling of the word "Tosto" can be explained with the International Phonetic Alphabet (IPA) phonetic transcription. The first syllable "To" is pronounced /toʊ/, while the second syllable "sto" is pronounced /stoʊ/. The "o" in both syllables is a diphthong, which means it has two vowel sounds blended together. The first vowel sound is pronounced as /o/ and the second vowel is pronounced as /ʊ/. Overall, the word "Tosto" is pronounced as /toʊstoʊ/ with a stress on the first syllable.