French is one of the most register-conscious languages in Europe. The same idea — "Do you want to eat something?" — can be expressed in at least three radically different ways depending on who you are talking to: Souhaiteriez-vous manger quelque chose ? to a client at a hotel, Tu veux manger quelque chose ? to a friend, and T'as la dalle ? (informal) to a teenage sibling. Pick the wrong one and you sound either pompous, rude, or simultaneously both. This page lays out the four main axes on which formal and informal French diverge — pronouns, verb forms, sentence structure, and vocabulary — and the social signals each carries.
The good news is that French speakers expect non-natives to err on the formal side. Being slightly too formal reads as polite or shy; being too informal with a stranger reads as disrespectful. As a learner, lean formal until invited to do otherwise. That invitation is often explicit: On peut se tutoyer ? ("Can we use tu?").
The vouvoiement / tutoiement axis
The single biggest register choice in French is vous vs tu. This is not just a grammatical pick — it is a social statement about the relationship between speaker and listener. Tu signals intimacy, equality, or that the addressee is a child; vous signals distance, deference, or that you are addressing more than one person.
Bonjour, vous allez bien ? Je peux vous aider ?
Hello, are you well? Can I help you? — A shopkeeper to a customer, or any first contact with an adult stranger.
Salut, ça va ? T'as besoin d'un coup de main ?
Hey, you all right? Need a hand? — The same offer between friends.
Madame Lefèvre, pourriez-vous me prêter votre stylo, s'il vous plaît ?
Mrs Lefèvre, could you lend me your pen, please? — A pupil to a teacher.
The default is vous with: adults you do not know, anyone older than you in a non-family context, clients, patients, students you teach, anyone in a position of authority (police, doctors, civil servants), and anyone in a service relationship where you are the customer. The default is tu with: family members (in most families), children, close friends, peers in informal contexts (other students, fellow guests at a casual party), pets, and increasingly, colleagues in tech / start-up / creative workplaces.
See tu vs vous for the full sociolinguistic map.
Nous vs on
In writing and formal speech, nous is the standard first-person plural: Nous partons demain ("We are leaving tomorrow"). In everyday spoken French, native speakers almost always replace nous with on + 3rd person singular verb: On part demain.
Nous vous remercions de votre patience.
We thank you for your patience. (formal — a customer-service email)
On y va ? On va être en retard.
Shall we go? We're going to be late. (informal — between friends)
Mes collègues et moi, on a décidé de prendre le train.
My colleagues and I decided to take the train. (informal but neutral — typical conversation)
The contrast is so strong that hearing nous in casual conversation between French people under fifty sounds slightly stiff. On is not slang — it is the unmarked spoken form. Nous is the unmarked written / formal form. (On has a second life as an impersonal "one / people in general", which exists in both registers: On dit que... "People say that...".)
Question forms: three levels
French has three ways to form a yes/no question, and they map almost perfectly onto register. From most formal to least formal:
| Register | Form | Example |
|---|---|---|
| Formal / written | Inversion (verb–pronoun) | Avez-vous une réservation ? |
| Neutral / standard | Est-ce que
| Est-ce que vous avez une réservation ? |
| Informal / spoken | Rising intonation only | Vous avez une réservation ? |
Souhaitez-vous régler par carte ou en espèces ?
Would you like to pay by card or in cash? — Formal inversion at a hotel reception.
Est-ce que tu veux un café ?
Do you want a coffee? — Neutral, works in almost any context.
Tu viens avec nous ?
Are you coming with us? — Intonation only; the default in casual speech.
A common informal variant adds -ti or, more often today, the question particle quoi at the end for emphasis (Tu viens, ou quoi ? — "Are you coming or what?"). Formal writing avoids both.
The disappearing ne
Standard written French uses two-part negation: ne ... pas, ne ... jamais, ne ... rien, ne ... personne, ne ... plus. In spoken French, the ne drops out constantly. This is one of the most reliable register markers: if you hear or see ne, you are in formal territory; if it is missing, you are in casual territory.
Je ne sais pas pourquoi il n'est pas venu.
I don't know why he didn't come. (written / formal)
J'sais pas pourquoi il est pas venu.
Dunno why he didn't come. (casual speech — note both *ne*-drops, and the *je* reduced to *j'*)
Y'a plus de pain, faut en racheter.
There's no bread left, we need to buy more. (very casual — *il n'y a plus* → *y'a plus*, *il faut* → *faut*)
Newspapers and serious magazines keep ne. Texts to friends, transcribed dialogue, social media posts, and most spoken French drop it. See explicit ne style for the contexts where ne is mandatory even in casual speech.
Vocabulary: same meaning, different worlds
Many everyday concepts have parallel words at different registers. Picking the wrong one is one of the fastest ways to crash a conversation — using bouffer at a job interview, or demeurer with your housemate.
| Formal / neutral | Informal / familier | Vulgar / very slangy | English |
|---|---|---|---|
| manger | bouffer | — | to eat |
| boire | picoler | se bourrer la gueule | to drink (alcohol) |
| partir | se barrer, se casser | se tirer, foutre le camp | to leave |
| habiter, demeurer | crécher | — | to live (somewhere) |
| l'argent | le fric, le pognon | la thune, le blé | money |
| une voiture | une bagnole, une caisse | — | a car |
| un homme / une femme | un mec / une meuf, un gars / une nana | — | a guy / a woman |
| la police | les flics | les keufs, les poulets | the police |
| du travail | du boulot, du taf | — | work |
| se moquer de | se foutre de | — | to make fun of / not care about |
| très | vachement, super, hyper | — | really, very |
Demeurer (formal) deserves a note: it is largely confined to administrative French ("Je demeure au 12, rue de Rivoli" on a form) or to literary register. In normal conversation, even formal, use habiter. Conversely, bouffer is universally informal — never use it in an email or with anyone you would address as vous.
Je vous prie de bien vouloir patienter quelques instants.
Please be so kind as to wait a few moments. (formal — at a reception desk)
Attends deux secondes, j'arrive !
Hang on a sec, I'm coming! (informal — to a friend)
Greetings and closings: ritual phrases
French is highly ritualised about how you open and close interactions. The wrong phrase is immediately noticeable.
| Context | Greeting | Closing |
|---|---|---|
| Formal letter to a stranger | Madame, Monsieur, | Je vous prie d'agréer, Madame, Monsieur, l'expression de mes salutations distinguées. |
| Formal email to known contact | Bonjour Madame Dupont, / Cher Monsieur Dupont, | Cordialement, / Bien cordialement, |
| Semi-formal email (colleague) | Bonjour Pierre, | Bien à toi, / À bientôt, |
| Casual message | Salut ! / Coucou ! | Bisous, / À plus, / Tchao, |
Bisous ("kisses") between friends and family is normal and not flirtatious — closer to "love" at the end of an English message to a relative. Tchao (the Italian ciao re-spelled) is very common in casual sign-offs.
Cher Monsieur, Je vous écris au sujet de votre annonce parue dans Le Monde du 14 mai.
Dear Sir, I am writing regarding your advertisement in Le Monde of 14 May. (formal job-application opening)
Salut Lucie, j'espère que tu vas bien ! Dis, t'aurais un moment cette semaine ?
Hey Lucie, hope you're well! Listen, would you have a minute this week? (casual message to a friend)
For the full inventory of closing formulas in correspondence, see La Correspondance Formelle.
The register sandwich: how to avoid mixing levels
The single most common French register error among intermediate learners is mixing levels in the same utterance. The result reads as either comical or jarring — like writing "Dear Sir, what's up?" in English.
❌ Bonjour Madame, est-ce que t'as l'heure ?
Incorrect mix — *bonjour Madame* is formal but *t'as* is informal. Choose one.
✅ Bonjour Madame, est-ce que vous auriez l'heure, s'il vous plaît ?
Hello, would you have the time, please? (formal throughout)
✅ Salut, t'as l'heure ?
Hi, do you have the time? (informal throughout)
The general rule: once you have chosen tu or vous, every grammatical and lexical choice downstream should match — ne-drop in casual, full ne in formal; bouffer in casual, manger in formal; salut with tu, bonjour Monsieur with vous. Picking carefully at the start saves you from constantly self-correcting later.
Where the line is moving
A few areas of French register are actively shifting in the 2020s:
- Workplace tu is spreading. Tech, advertising, consulting, and creative agencies now often default to tu among colleagues regardless of age or hierarchy. Traditional sectors (banking, law, civil service, education) still default to vous.
- Email closings are getting shorter. Old-school Je vous prie d'agréer... is still used in administrative correspondence, but in business email, Cordialement has become the unmarked default. Bien cordialement is slightly warmer, Cordialement by itself is neutral, and Cdt is text-speak that some find too curt.
- Customer-service speech is moving towards vous
These shifts are gradual; in formal writing and with older interlocutors, the conservative norms still hold.
Common Mistakes
Mistake 1: Using tu with a service worker your own age.
❌ (to a waiter) Tu peux m'apporter l'addition ?
Incorrect register — even with a young waiter, the service relationship requires *vous* in standard French.
✅ Vous pourriez m'apporter l'addition, s'il vous plaît ?
Could you bring me the bill, please?
Mistake 2: Saying nous in casual conversation.
❌ Nous sommes allés au cinéma hier soir avec Paul.
Grammatically perfect, but stylistically too written — between friends, this sounds like reading from a homework assignment.
✅ On est allés au ciné hier soir avec Paul.
We went to the cinema last night with Paul.
Mistake 3: Keeping ne in every spoken sentence.
❌ (in conversation) Je ne sais pas, je n'ai pas vu, il n'a rien dit.
Hyper-correct — natives will understand but you sound like you are reciting a textbook.
✅ J'sais pas, j'ai pas vu, il a rien dit.
Dunno, didn't see, he didn't say anything. (natural casual speech)
Mistake 4: Translating English politeness directly with familiar vocab.
❌ Cher Monsieur, je voudrais bouffer dans votre restaurant samedi soir.
Comically inappropriate — *bouffer* is slang for 'to eat / to stuff one's face'. Never use it in formal writing.
✅ Cher Monsieur, je souhaiterais réserver une table dans votre restaurant samedi soir.
Dear Sir, I would like to reserve a table at your restaurant on Saturday evening.
Mistake 5: Using inverted questions in casual conversation.
❌ (to your roommate) As-tu acheté du pain ?
Grammatically correct but stilted — inversion between roommates sounds like a 19th-century novel.
✅ T'as acheté du pain ?
Did you buy bread?
Key takeaways
The formal–informal divide in French runs along four parallel axes that move together: pronouns (vous / tu, nous / on), verb-level grammar (full ne / ne-drop, inversion / intonation questions), vocabulary (manger / bouffer, argent / fric), and ritual phrases (Madame, Monsieur / Salut). Pick a register at the start of an interaction and keep all four axes consistent.
For learners, the safest default with strangers and in writing is formal; the safest default with friends, family, and peers your own age is informal. Watch for the explicit invitation on peut se tutoyer ? — that is when you switch. And remember the single biggest spoken-French upgrade: replace nous with on in everything you say to people, and drop ne in negation. Those two changes alone account for most of the gap between textbook French and the way actual French people talk.
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Start learning French→Related Topics
- Les Registres du FrançaisB1 — French operates on a four-register spectrum from soutenu (literary) through courant (standard) and familier (casual) to populaire (slang). Mastering register — knowing which lexicon, grammar, and syntax fits which situation — is what separates a functional speaker from a fluent one.
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