The odd words oïl and oc were words for “yes.” “Oïl” (ancestor of modern French “oui”) was a corruption of the Latin “hoc ille,” meaning “that’s it,” and “oc” came from Latin “hoc,” meaning simply “that.” Most other Romance languages use “si,” from Latin “sic” [so] for “yes.” Even the French use it to refute a negative assertion.
Many of the differences between the French of the north, including the Norman French spoken for several centuries in England, and the south can be traced to the time of the Roman conquest. The Romans annexed and colonized portions of southern France nearly a century before they reached northern Gaul. The south was understandably more Latinized in speech and culture than the northern regions.
Later, the Langue d’oïl dialect of Paris became the court language and began to replace the Langue d’oc varieties. But even as late as the French Revolution (1789), it is estimated that no more than 25 percent of the French population spoke Parisian French natively. Even today, Provençal and Catalonian survive in the south despite successive attempts to impose standard language and education throughout France.
There still are Celtic speakers in Brittany, but their language is not native to France. As the name indicates, these Celtic speakers were refugees from Great Britain fleeing the invading Angles, Saxons and Jutes in the fifth Century A.D. Only a few words remain in French from the pre-Roman Celts, among them mouton (sheep), chemin (road) and charrue (plow).
The ancient divisions between north and south still appear in Modern French. In the northern areas of France with strong Germanic influence, one finds names like Neufchâteau and Francheville, in which the adjective precedes the noun as it does in the Germanic languages like English or German. In the south of France with its stronger Latin influence, these become Châteauneuf or Villenueve.
Of all the Romance languages, French has moved farthest from its parent Latin, even though more than 80 percent of French vocabulary still can be traced back to spoken, or vulgar, Latin. The northern French also appear to have lost the ability to understand spoken Latin very early. The Oaths of Strasbourg, a pact between Charles the Bald of France and Louis the German, published in A.D. 842 in the French and German vernaculars of that early time showed the need for both parties to understand the agreement in their own language.
Taken from Galveston County Daily News: 24.07.11