Found this academic paper (link is a PDF, sorry) kind of interesting. Generally in Indo-European languages (and certainly with the Romance languages) we talk about them starting out with three grammatical genders (neuter, masculine, feminine) with many of the descendent languages simplifying into fewer. But this paper takes evidence from a number of dialects in South-Central Italy1 to argue that these dialects have four genders, splitting the Latin neuter into an “alternating neuter” (like in Romanian, or much more restrictedly in Italian – words that act grammatically masculine in singular but feminine in plural) as well as an “abstract neuter”, for uncountable things. Also these categories are still productive (i.e. new words get assigned to them), unlike Italian, where the category of “words that act masculine in singular but feminine in plural” is closed off to new words.
Note, not necessarily dialects of Italian, but Romance language varieties that share some mutual intelligibility with each other and with standard Italian (and other big varieties of the region like Neapolitan, etc.) ↩︎