Present Tense:
* Informal: "On a" (we have, literally "one has")
* Formal: "Nous avons" (we have)
Past Tense:
* Informal: "On avait" (we had)
* Formal: "Nous avons eu" (we have had, literally "we have had")
Future Tense:
* Informal: "On aura" (we will have)
* Formal: "Nous aurons" (we will have)
Examples:
* Informal: "On a beaucoup de travail." (We have a lot of work.)
* Formal: "Nous avons un rendez-vous." (We have an appointment.)
* Informal: "On avait besoin de plus de temps." (We needed more time.)
* Formal: "Nous avons eu une bonne journée." (We had a good day.)
* Informal: "On aura bientôt fini." (We will be finished soon.)
* Formal: "Nous aurons un nouvel ordinateur." (We will have a new computer.)
Remember that the informal "on" is more commonly used in spoken French, while "nous" is more formal and often used in writing.