What proposition is used in the french language for provinces?

There is no specific proposition used for provinces in the French language. The preposition used will depend on the context and the verb used.

Here are some examples:

"En" (in): This preposition is used to indicate location within a province.

* "Je suis en Normandie." (I am in Normandy.)

"De" (from): This preposition is used to indicate origin from a province.

* "Il vient de Bretagne." (He comes from Brittany.)

"À" (to): This preposition is used to indicate movement towards a province.

* "Nous allons à Provence." (We are going to Provence.)

"Dans" (in): This preposition is used to indicate location within a province, but can also be used for regions that are not provinces.

* "Il y a beaucoup de vignobles dans le Languedoc-Roussillon." (There are many vineyards in Languedoc-Roussillon.)

"Sur" (on): This preposition is used to indicate location on a specific part of a province.

* "Le château est situé sur la côte de la Manche." (The castle is located on the coast of the English Channel.)

Ultimately, the best preposition to use will depend on the specific context of the sentence.