Like Old French, from the 9th to the 13th century, Old Occitan preserved the two-case system of Vulgar Latin, subjective and objective, and it seems that until the middle of the 12th century, the written and spoken languages were identical. Then, the distinction between the cases disappeared in spoken usage, though they still persisted in the written texts of the Trobadors. This period can be qualified as the Golden Age or the time of the Trobadors.

A second period ranges from the beginning of the 14th century to the middle of the 16th. It is characterized by the dropping altogether of the flexions in witten texts, by the beginning of dialectization, the dropping of courteous vocabulary and the use of learned words borrowed from Latin and Greek to express law, medecine, philosophy and theology. Occitan was no longer a literary language, but it was used to write the deeds, the accounts, the chronicles and the resolutions of local communities. Since the second half of the 16th century to our days, Occitan was banned from written documents, and reduced to oral usage only, mainly by country and working people, in their everyday life, at work or at home.