Short answers, pulled from the story.
Corsican is a Romance language classified as Italo-Romance, closely related to the Tuscan dialects of central Italy. It is mutually intelligible with standard Italian, which is based on Florentine, a sister dialect to Corsican.
French formally replaced Italian as Corsica's official language on the 9th of May 1859, although France had acquired the island from the Republic of Genoa in 1768. French literacy began spreading widely through the Jules Ferry laws from 1882 onward.
A 2013 survey of Corsica's population of 309,693 found between 86,800 and 130,200 speakers of Corsican. Twenty-eight percent of the population could speak it well, while 90 percent supported a French-Corsican bilingualism.
The two main dialect groups are Northern Corsican, spoken around Bastia and Corte, and Southern Corsican, spoken around Sartène and Porto-Vecchio. They are separated by a dialect line running roughly from Girolata to Porto-Vecchio. A transitional zone lies between them, and the dialects of Calvi and Bonifacio belong to the Ligurian language rather than to Corsican.
Yes. Gallurese and Sassarese, spoken in the extreme north of Sardinia, are Italo-Romance varieties thought to derive from migration by Tuscanised Corsicans. On the 14th of October 1997, Sardinian regional Law Number 26 granted both dialects equal legal status with Sardinia's other indigenous languages.
The Riacquistu, meaning "reacquisition," is a cultural movement that emerged in the 1970s for the rediscovery of Corsican culture and language. It produced new theatre, including Dumenicu Togniotti's Teatru Paisanu, which staged polyphonic musicals from 1973 to 1982, and new prose literature by writers such as Marcu Biancarelli. According to anthropologist Dumenica Verdoni, writing in Corsican is an integral part of affirming Corsican identity.