Le pronom "on"
"On" can be an informal "nous" OR a "one",
In any cases, "on" is conjugated like elle/il/ça (3rd person singular)
There's no exception.
HOW TO CONJUGATE "ON"?
Be careful to differentiate the meaning of "on", and the form that its conjugation takes,
they are not the same!
It's a "we" that has a 3rd person conjugation-form, but it doesn't give it the meaning of a 3rd person!!! It's only the written form.
On mange, on joue, on dort.
Elle mange, elle joue, elle dort.
Il mange, il joue, il dort.
ça mange, ça joue, ça dort.
Nous mangeons, nous jouons, nous dormons.
ON MEANING WE
In informal, unwritten conversation, it's very frequent to use "on" instead of "nous".
Some people keep saying it's not correct French, but it's perfectly correct, it's informal, but not slangish at all. You can use it with your teacher in the classroom.
ON MEANING ONE
"On" can be the informal pronoun.
For instance: "One does not change a team that wins" (It's more than probable that the English "one" used for this is from the French "on")
Examples of uses
Informal we, conjugated like a he/she/it. (identified people)
A general saying, including everyone (but no identified person)
can be a proverb, or a general statement, not informal at all in this case:
On est lundi. (formal: Nous sommes lundi). Here it's a "we", but also a general statement.
Would be equivalent to the impersonal "C'est lundi".
On perd la mémoire quand on prend de l'âge. (a general truth or a proverb)
One loses his memory when getting older.
Ici, on parle français.
Here, French is spoken.
Il faut qu'on parle.
We must talk together.
C'est comme ça qu'on fait.
It's the way it must be done.
Here: on = everybody. A general statement.
WARNING: THE INFORMAL "ON" IS NOT A "IT"
Even if it's often a person we don't know (when it's the impersonal) "on" is not "it" because it's a person. (opposed to "ce", "ça", "cela"),
"on" is often translated by "it" (when it's not by "we" or "one"), but it's an impersonal =not a particular person who makes the action), but still a person, not a "it".
We don't know this person.
It's not a neutral in the sense that it can't be a thing, it's always a person. See it as an impersonal "we".
Imagine: We (human beings) are forced to work to live. With a very general meaning.
TRANSLATING THE PASSIVE VOICE
"On" can be used when you don't know the subject, to translate the passive voice in English, but it's not a passive voice, it's an active voice, the subject is "on".
"Cashier wanted" = On demande un caissier (voix active, impersonnelle) = Un caissier est demandé (voix passive)
Correct me if I'm wrong, but if you are using 'on' to mean 'we', and are conjugating a verb in a compound tense (e.g. passé composé, passé antérieur, futur antérieur etc.) and it takes 'etre' as the auxiliary, the past participle has to add an s on to the end since the subject implied is plural. For example:
We (informal) went to the shop. = On est allé(e)s au magasin.
This means it would not be treated entirely the same as a verb used with il/elle. Let me say again though that I'm not sure about this.
When I learned french "on" was for "one" or "everyone". So, We never used it as much as "nous". Now, that I know that "on" is used more I will remember that. :) I was also taught that "Il faut que" meant "it is necessary". So, for the usage of "must" it would be "Dois" "Je dois telephoner ma mere". ( I must call my mother). "Il faut que marcher tous les jours" (It is necessary to walk every day). So, it just seems odd to me to use il faut que for "must" instead of "Je Dois". There are so many ways of saying things that it was taught to me like this to "simplify" things when learning the language. I was told "must" is "stronger" form of "have to" Vous devez manger"! (You must eat) because it's for survival. "il faut que" it's necessary, but not for "survival". I'm GRATEFUL that you put this explanation of "on" being used. I'm learning "new" ways to use french all the time. :) Thanks Perce_Neige! :) You're HELP is GREATLY appreciated! :)
It's the difference between French taught in schools and real French.
(And often, I'm a kind of purist for a lot of grammatical topics)
It depends which kind of French you talk. There is several registers of languages, in everyday French "on" is valid for "nous". And you will meet this use a lot...
So, you have to learn it.
In very formal French, it's wrong. If you write a letter to your teacher, your boss, etc.. it should be avoided to remain formal.
It's like "il/elle/ça", so it's "se".
On nous lave = someone else wash you, not a reflexive.
Everything is like il/elle/ça in the form, but everything is like "we" in the meaning.
Reflexive: On se lave. Nous nous lavons.
Meaning: We wash ouselves, or One washes oneself.