Short answers, pulled from the story.
Basque is the only known language isolate in Europe, meaning it has no traceable relationship to any other living or known historical language. It is also the only surviving pre-Indo-European language in Europe, predating the arrival of Celtic and Romance languages in the region.
According to the 2021 sociolinguistic survey, 806,000 people spoke Basque, representing 30.6 percent of the total Basque-territory population aged 16 and above. The largest share, 756,000 speakers (93.7 percent), live in the Spanish part of the Basque Country, with 51,000 speakers (6.3 percent) in the French portion.
Franco's government suppressed Basque from official discourse, education, and publishing. It was made illegal to register newborns under Basque names, tombstone engravings in Basque were required to be removed, and people were fined for speaking the language in public in some provinces.
Euskara Batua is the standardised form of the Basque language, developed by the Euskaltzaindia (Royal Academy of the Basque Language) in the late 1960s. It was created so that Basque could be used in formal contexts such as education, mass media, and literature, and easily understood by speakers of all dialects.
The Roncalese dialect of Basque went extinct in 1991 when its last speaker, Fidela Bernat, died. It had been spoken in seven villages of the Roncal Valley.
In the Basque Autonomous Community of Spain, Basque is co-official alongside Spanish under the Statute of Autonomy. In Navarre, it holds co-official status only in the Basque-speaking northern zone under the Ley del Vascuence. In the French Basque Country, Basque has no official status and French citizens cannot use it in a French court of law.