1. Introduction to Old French
Brigitte L.M. Bauer
and Jonathan Slocum

2. Language d’oïl & Langue d’oc
"Old French" refers to a collection of dialects spoken from the 9th through 13th centuries.
it is possible to divide them in two groups:
the dialects spoken in the northern parts of France, to which one refers as language d'oïl
those spoken in the Southern parts, referred to as langue d'oc. Oc and oïl were markers of affirmation ('yes') in the respective dialect groups.
La language d'oïl includes the following dialects
the dialects of Picardie (le Picard), Normandy (le Normand), Ile de France (le Francien), Lorraine (le Lorrain), Anjou (l'Angevin), Poitou (le Poitevin), Bourgundy (le Bourguignon), and Berry (le Berrichon).
La langue d'oc includes the dialects of the following regions
Provence (le provenc/al), Auvergne (l'auvergnat), Gascony (le gascon), and Languedoc (le languedocien).

3. Grammatical Characteristics
Old French represents an intermediate stage between Latin and the modern language
In OF, use of the subject pronoun is infrequent
OF uses the definite article, though not as frequently as modern French
Negation: ne but no pas
Word order is predominately Subject-Verb-Object

4. End of Old French
By the end of the 13th century, the dialect of Old French used on the Ile de France predominates.
The language used during the 14th and 15th centuries in France is referred to as Middle French and is much closer to modern French.

5. Source
Old French Online (