Where does “interessantissimo” come from?

interessantissimo (Italian) comes from Italian interessante, from Italian interessare, from Italian -are, from Latin -ō, from Proto-Indo-European -ō — Derives nouns from roots.

Ancestry of “interessantissimo”, step by step

StepLanguageWordMeaning
1Italianinteressanteinteresting; present participle of interessare
2Italianinteressareto be interesting, to be of interest, to...
3Italian-areUsed, with a stem, to form the infinitive of most...
4Latinsuffixed to nouns or adjectives. Originally a-stem nouns. Later extended to nouns with other stems. Forms regular first-conjugation verbs
5Proto-Indo-EuropeanDerives nouns from roots
Every word from Proto-Indo-European Every word from Latin Every word from Italian -are