The influence of Latin is stronger as one gets closer (either chronologically or geographically) to the historic heart of the Roman Empire. Northern French, Romanian and Portuguese, being farther from Rome, mutated more than Spanish, which mutated more than Catalan, which mutated more than Provençal, which mutated more than Piedmontese, which mutated more than Lombard, which mutated more than Florentine.

The time at which many of these Medieval works were written, whether or not French was pronounced as it was written, most of the letters that later drop out of French were still written: Et si com je gisoie en cel lieu dont vous avés oi parler, si fu entre le joesdi absolu et le venredi beneoit, et si avoie je a Nostre Signour dit le service que on apele tenebres, et lors me prist mout grant volenté de dormir... which in Modern French is translated as: Et tandis que j'étais couché dans cet endroit dont vous venez d'entendre de parler - c'était entre le Jeudi et le Vendredi saints, et j'avais pour Notre Seigneur célébré l'office qu'on appelle Ténèbres - il me prit une fort grande envie de dormir...