How do you say to write a paper in french?

There are a few ways to say "to write a paper" in French, depending on the context and level of formality:

Formal:

* Rédiger un mémoire: This is the most formal way to say it, and it implies a long, academic paper.

* Rédiger un rapport: This also implies a formal paper, but it can be shorter than a mémoire.

* Rédiger un document: This is a more general term for writing any kind of document, including a paper.

Informal:

* Écrire un devoir: This is a more casual way to say "to write a paper", often used in the context of school assignments.

* Écrire un texte: This is a very general term for writing anything, including a paper.

Example sentences:

* Je dois rédiger un mémoire sur l'histoire de la France. (I have to write a paper on the history of France.)

* Le professeur nous a demandé de rédiger un rapport sur nos recherches. (The professor asked us to write a report on our research.)

* J'ai écrit un texte sur la pollution atmosphérique. (I wrote a paper about air pollution.)

The best way to say it depends on the specific situation. If you're unsure, it's always best to err on the side of formality.