Plural adjectives + noun

Question

In the following sentence, why is it formalità for a plural, while adjectives are ending with 'e'?

Si compiacque di provvedere alle più minute formalità del servizio.

Answer 1

The noun formalità is feminine like all abstract nouns with the tonic accent on the last syllable such as virtù bontà felicità libertà.

These nouns are invariable in the plural for etymological reasons, for they derive from Latin nouns with the drop of the final syllable. In the Divina Commedia we find alternating use of virtù and virtute, for instance. In modern Italian the “undropped” form is never used.

Thus it is la formalità or una formalità (singular) and le formalità (plural). In the sentence you quote, the adjective minuto (in English, subtle) has to be in feminine plural form, hence minute.

By the way, the usage of the graphic accent in oxytone words derives from the necessity to denote somehow the dropping of the final syllables in this class of words. At the beginning with an apostrophe, which later moved above the vowel because of other oxytone words, typically conjunctions such as perché poiché affinché that have different origin and no dropped syllable.

Answer 2

Nouns ending in vowels with an accent have the same form in singular and plural.