What is informal French?

When you start learning French, you usually begin with standard French: the kind used in textbooks, exams, and school.

You learn to say:

“Bonjour, comment allez-vous ?”

“Je suis désolé, je n’ai pas compris votre question.”

That’s great. It’s important.

But it’s only one part of the French language.

Because in real life, French people don’t speak like in textbooks.
 

🗣️ Informal French is everyday spoken French

It’s the kind of French you use:

  • with friends
  • with family
  • on the phone
  • in a WhatsApp message
  • in a relaxed conversation

It’s a more spontaneous, direct, and lively French.

Sentences are often shorter, words are sometimes transformed, we play with sounds, we invent, we shorten things.

Par exemple :

“Tu es au cinéma ?” devient “T’es au ciné ?”

(= “Are you at the movies?” becomes a shorter and more natural version)

“Il est énervé” devient “Il est vénère.”

(= “He’s angry” becomes a slang twist of the original sentence)

What about French slang?

Slang is a coded language, originally created by certain social groups to avoid being understood by others.

Originally, it was used by thieves, outsiders, soldiers… kind of like a secret French to identify with a group or “clan.”

But today, many slang words have become part of everyday language, especially among young people.

It’s a French that is colorful, sometimes funny, often very expressive, and it helps you express things faster, stronger, or with more emotion.

Par exemple :

  • “un flic” = a cop
  • “se barrer” = to leave, to get out
  • “piquer” = to steal
  • “être crevé” = to be very tired

💡 Note: Some slang terms can be a bit vulgar or very informal. You shouldn’t use them in a job interview, for example 😅

But understanding slang is essential to follow a French series, understand conversations between young people, or catch jokes in real life.
 

🚫 It’s not “bad French”

Many people think that slang or informal French is incorrect.

But that’s not true.

It’s not a mistake — it’s a code, a style, another way to express yourself.

Just like in English, when someone says:

“I’m gonna chill tonight.”

That’s not incorrect, it’s informal. And if you want to understand native speakers, you need to understand this kind of language.
 

🎯 Your goal: understand it (and maybe use it later)

You don’t need to speak in slang or use it all right away.

But you do need to understand what others are saying.

Why?

Because this is the kind of French used in the streets, in TV series, in podcasts, in spontaneous conversations.

And if you really want to fit in, understand jokes, and follow dialogues without subtitles, it’s essential.

To sum up:

  • Informal French is real-life French
  • It’s essential to understand native speakers
  • And it’s not “bad French”, it’s a different kind of French: more personal, more natural

Now, let’s move on to practice: here are the essential expressions you absolutely need to know to understand French people when they speak... with each other.
 

👉 Griller quelqu’un

= to catch someone doing something (usually something sneaky or wrong)

“Je l’ai grillé en train de mentir à la réunion.”

(I caught him lying during the meeting.)

Good to know:

  • You can also be “grillé” if you’re cheating, flirting with someone else, or sneaking a peek at answers during a test.
  • Very common in informal and playful situations.

🗣️ Real-life example:

— T’as vu Bastien hier ?

— Ouais. Je l’ai grillé en train de mater les réponses sur son téléphone pendant le test !

👉 Relou

= annoying, frustrating, or a pain (verlan of “lourd”)

“Il est relou avec ses blagues nulles.”

(He’s annoying with his lame jokes.)

Good to know:

  • “Relou” is a super versatile word used to describe anything (or anyone) that wears you out or gets on your nerves.
  • You can say a film is “relou”, a rule, a task, a person—basically, anything mentally exhausting.

🗣️ Real-life example:

— J’ai encore un contrôle demain…

— Roh, c’est relou ! T’as pas une pause un peu ?

👉 Bosser

= to work (informal version of “travailler”)

“Je bosse demain matin.”

(I’m working tomorrow morning.)

Good to know:

  • Widely used even in professional contexts, especially among colleagues.
  • Less formal than “travailler”, but not rude at all.

🗣️ Real-life example:

— Tu viens boire un verre ce soir ?

— J’aimerais bien, mais je bosse tôt demain…

👉 Se marrer

= to laugh, have fun, crack up

“On s’est bien marrés hier soir !”

(We had a good laugh last night!)

Good to know:

  • You might also hear it in the past or imperfect tense: “On se marrait bien quand on était gamins.”
  • Very common, very positive—often describes a great shared moment.

🗣️ Real-life example:

— Alors, ton week-end ?

— Trop bien ! On s’est bien marrés, ça faisait longtemps.

👉 Avoir la flemme

= not feeling like doing something, being tired or unmotivated

“J’ai la flemme de sortir.”

(I don’t feel like going out.)

Good to know:

  • “La flemme” isn’t laziness—it’s more like mild mental fatigue or a temporary lack of motivation.
  • It can also be used humorously or in an exaggerated way: “J’ai la flemme de respirer aujourd’hui…”

🗣️ Real-life example:

— Tu veux aller courir ?

— Là tout de suite ? J’ai trop la flemme, on se fait un film ?

👉 Se planter

= to mess up, to make a mistake

“Je me suis planté de train.”

(I took the wrong train.)

Good to know:

  • Used for silly or annoying mistakes—not serious, but still a problem.
  • Also used in the future or past: “Je vais me planter, c’est sûr…”

🗣️ Real-life example:

— C’était à quelle heure le rendez-vous ?

— 14h30.

— Mince ! Je me suis planté, j’ai dit 15h à tout le monde.

👉 Ouf

= crazy (verlan for “fou”), but also: amazing, shocking, incredible

“C’était un truc de ouf !”

(That was insane!)

Good to know:

  • It’s very expressive. It can be positive or negative depending on the situation:
    • “Ce concert était ouf !” (positive)
    • “La facture ? 3000 euros. Un truc de ouf.” (negative)

🗣️ Real-life example:

— T’as vu les images de l’orage hier soir ?

— Oui ! Un truc de ouf, j’ai jamais vu ça !

And to help you even more, I’ve got a little gift for you!

I’ve prepared a free PDF with the 50 most common French slang words.

These are words you’ll hear in the streets, in TV shows, in native conversations…

👉 It’s the perfect tool to finally understand real spoken French and never feel lost again when a French person talks to you.

Download your PDF now and start sounding (and understanding) like a real French speaker 🇫🇷