Of the work of the Boccaccio school in the Neapolitan period, that written in verse was written in a language and style which is much more immediate that the language and style of the prose work. The language of Caccia di Diana is not markedly poetic with the exception of the presence of rare monophthong forms, very rare phonetic or lexical Latinisms and equally rare morphological Sicilianisms. Similarly, the octaves of the Filocolo were written in a language which can be considered medium in both phonomorphological and lexical terms. Thus in neither one nor the other does Boccaccio pursue anti realism. Rather the prose of the Filocolo is crowded with mythological and metaphoric disguises embellished with Latinisms and supported by a complex syntax packed with inversions and other modules which imitate the Latin period such as coniunctio relativa and the declarative phrase constructed with the accusative and the infinitive. After an overview of judgements relative to the work written in the Florentine period, from which it emerges that the linguistic and stylistic panorama is similar, the author moves on to analyse certain sequences from the Decameron and VI 10 37-52 in particular, an extraordinary example of Boccaccio’s ability to sound out all the expressive potential of his contemporary Florentine from the sophisticated language which evoked the elegance of Latin to the colloquial or low Florentine which echoed the noisy, humorous daily language of the squares and marketplaces.