How does language change over time? How did 18th-century French change compare to 12th century French? But when we talk about language change, that's very misleading. I mean, up until the turn of the century, you could find people in nearby villages in France with virtually could not understand one another. The idea of a national language is a pretty modern phenomenon. It has to do with the rise of nationalism, and communication, and so on.

The factors that intervened and continue to intervene in the change of language, have been mainly wars, idioms and also the cultural exchange with other languages.

Explanation:

Regarding wars, it happens that hostilities cause people's mentality to change and the language is a reflection of this. The word ‘nazi’, for example, arises in World War II. Regarding fashion, some words become preferred in use and others that used to have that meaning have new values. The word "dog" means dog in English, but in past centuries the word "hound" used to be used, which now only remains to talk about hounds.

The predominant one during the twelfth century was the ancient French, which evolved through time until it reached modern French in the eighteenth century, which remains in force until today. The alteration in the pronunciation of ancient French could be the fact of the contribution of non-Romans, in this case Celts and Germans and the constant wars with Italy an important factor for this to evolve into modern French.