How do you say we have to in french?

There are several ways to say "we have to" in French, depending on the context and level of formality:

Formal:

* Il faut que nous... (It is necessary that we...)

* Nous devons... (We must...)

* Nous sommes obligés de... (We are obliged to...)

Informal:

* On doit... (We have to...; this is a more casual and general form)

* Il faut... (We have to...; this is also informal and commonly used)

* Faut qu'on... (We have to...; this is even more informal and common in spoken French)

Examples:

* Formal: "Il faut que nous étudions pour l'examen." (We have to study for the exam.)

* Informal: "On doit aller au supermarché." (We have to go to the supermarket.)

* Very Informal: "Faut qu'on mange quelque chose." (We have to eat something.)

The choice of the correct phrase depends on the specific situation and the relationship between the speakers.