information:filtering, structural:expansion, stylistic:tone, quality:corruption
Phonology

Compared with most other Romance languages, Italian has many inconsistent outcomes, where the same underlying sound produces different results in different words, e.g. laxāre > lasciare and lassare, captiāre > cacciare and cazzare, (ex)dēroteolāre > sdrucciolare, druzzolare and ruzzolare, rēgīna > regina and reina. Although in all these examples the second form has fallen out of usage, the dimorphism is thought to reflect the several-hundred-year period during which Italian developed as a literary language divorced from any native-speaking population, with an origin in 12th/13th-century Tuscan but with many words borrowed from languages farther to the north, with different sound outcomes. (The La Spezia–Rimini Line, the most important isogloss in the entire Romance-language area, passes only about 30 kilometres or 20 miles north of Florence.) Dual outcomes of Latin /p t k/ between vowels, such as lŏcvm > luogo but fŏcvm > fuoco, was once thought to be due to borrowing of northern voiced forms, but is now generally viewed as the result of early phonetic variation within Tuscany.