Towards the end of the XIII Century, French language had divided in two main dialects: öil language, spoken in the North side of the Loire River, and oc language, spoken in the South (öil and oc mean yes in both dialects). The most important difference was the pronunciation of vowel a from Latin, which remained unaltered in the Southern language (particularly in the main dialect, Provençal), but became e in the Northern one. For example, the Latin word mare was pronounced mer in öil language and mar in oc language.

Within the setting of each one of these languages a series of dialects were developed and remained alive for a while. Provençal gave birth to a rich literature in the Middle Age and seemed to acquire more importance than the Northern language, but lately, after the XII Century, it started to loose it. Nowadays there are about 500 words left of the original language, which are incorporated into modern French, like bague ("ring"), velours ("velvet"), cadeau ("gift").

The öil language divided in so many dialects as regions were formed in the North of France (Île de France, Normandie, Picardy, Poitou and Bourgogne). Out of these the one from Paris (Île de France) imposed itself, as the city grew in political and economical importance. Modern French evolved directly from that language. During the next 200 years, French became more and more popular in Europe and was considered the language of culture among European nobility, to the point that many foreign princes started to study it. In the XIV and XV centuries it became the national language of France, as a symbol of unity against the English during the Hundred Years War, but it was not until the XVI Century when it became official by royal order. From the XVII century onwards, the language acquired its maximum splendor. First, thanks to the works of the poet François de Malherbe; and second, with the compilation of the first dictionary by the French Academy (literary society formed in 1635 by Cardinal Richelieu), which first volume saw the light in 1694. During the many wars that battled France against Italy, Germany and Spain in that time, French enriched its vocabulary. During Louis XIV's kingdom, French language became the language of diplomacy and scientific research at an international level. From this century onwards, it can be said that modern French was born. It's the same one used today, except slight variants, mainly for the tendency of expanding French vocabulary to indicate new objects and concepts. Since the second half of the XIX century, its main source of new terms has been the English language and scientific and technological terms (such as automobile, jet, photographie, and télégraphe). Nowadays, French language is one of the working languages of the Secretary of the United Nations.