Meaning of “Si” in French — French Vocabulary Lesson

Si” is a small French word of many meanings.
French people use it a lot, for totally unrelated sentences. It can be easy to feel confused!
How can you use the word “Si” in French? And what does it really mean?
What rules does it follow, and in which sentences can it crop up?
Let’s dive in with these explanations and examples!

Learning goals: This is what you’ll be able to do after watching this lesson

  • Beginner: Use “Si” to say “Yes”
  • Intermediate: Use “Si” to say “If”
  • Advanced: Use “Si” to say “So much”

Bonjour I’m Géraldine, your French teacher.
Welcome to Comme une Française.
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1) “Si” = If

In most sentences, Si means “If.”

We use it in sentences made of two parts. Those two parts most often are:

  • A part that starts with Si + le présent + a part with le présent
    Si je gagne, j’achète une voiture. (= If I win, I’ll buy a car.)
  • A part that starts with Si + le présent + a part with le futur
    → Si tu viens, tu seras tout seul. (= If you come, you’ll be all alone.)
  • A part that starts with Si + l’imparfait + a part with le conditionnel
    → Si j’étais riche, j’achèterais une nouvelle voiture. (= If I were rich, I’d buy a new car.)

(Or “Si + le passé composé” + a part with passé composé or présent or futur.)

You can find the whole conjugation of le conditionnel présent here.

We use le conditionnel in a sentence with “Si”, or on its own for politeness (to soften an affirmation) – just like in English!

For example:
Si j’étais là, je serais heureux.
= If I were there, I’d be happy.

Je voudrais une baguette, s’il vous plaît.
= I’d like a “baguette”, please.

→ You can learn more tenses and conjugations, with step-by-step quizzes to test yourself and help you learn, with my special program “Test Your Conjugation”.

Le conditionnel is NOT just used after Si, but in the other part of the sentence as well. As the French school kids’ mnemonic goes: “Les “Si” n’aiment pas les “-rais.”” (= “Si” doesn’t like “-rais”, the endings for the conditional)

It’s also a cute mistake by a kid character in the famous French movie la Guerre des Boutons : “Si j’aurais su, j’aurais pas venu.” This catchphrase should be “Si j’avais su, je ne serais pas venu.” (= If I’d known, I wouldn’t have come), but the kid is young and innocent so he messes up French grammar.

Check out my recommendations for more old French comedies here!

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You can use Si (= “If”) in many everyday expressions or turns of phrases that you’ll find in English as well. For example:

  • Même si (= Even if)
  • Je viendrai même si je suis malade. (= I’ll come even if I’m sick.)
  • Si seulement (= If only)
  • Si seulement je pouvais ! (= If only I could!)
  • Comme si (= As if)
  • Comme si c’était une surprise ! (= As if it were a surprise!)

We also use “Si” in its contracted form (when it comes before the vowel i) in the expression s’il te plaît / s’il vous plaît (= please) !

Discover more ways to say thank you in French
Learn more common, polite French greetings

2) “Si” = Yes ! (After a negative question)

In French, we use Oui to say “yes,” most of the time. For example:
“Tu as faim ?” “Oui !” (= “Are you hungry?” “Yes I am!”)

We don’t add a verb after “Oui” … which can be confusing after a negative question.

For example, take the question: “Tu n’as pas faim ?” (= Aren’t you hungry?)

If you answer “Oui”, do you mean “Yes, I’m hungry,” or “You’re right, I’m not hungry” ? If you use “Non”, does it mean “No, I’m not hungry” or “No, you’re wrong, I’m not hungry” ? It’s not a big problem, but it can make for blurry conversations.

French language resolves that ambiguity by using another word to mean “yes” after a negative question: Si !

For example:

“Tu n’as pas faim ?” “Si !” (= “Aren’t you hungry?” “, Yes, I am hungry.”)

It’s also used to deny a negative affirmation!

“Tu n’es pas allé à l’école aujourd’hui.” “Si !”
(= “You didn’t go to school today.” “Yes, I did!”)

→ Can you think of other examples of questions where you can answer “Si !” in French? Write them in the comments below!

3) “Si” = So much

Finally, “Si” is also used to mean “So” or “So much.” For example:
Je suis si heureux de te voir ! (= I’m so happy to see you!)

It is kind of formal, though. In everyday spoken French, we’d rather use “tellement” instead. For example:

Je suis tellement heureux de te voir ! (= I’m so happy to see you!)

That’s how Si is used in the famous French jazz song C’est si bon (= “That’s so good!”) that’s been covered by Louis Armstrong or Yves Montand, among others. Nowadays we could also say C’est tellement bon or C’est tellement bien in everyday French – but it doesn’t fit as well in a verse!

4) The extra mile : other uses of “Si” and “If”

Le “Si” is also a musical note in most languages. It’s part of la gamme (= the musical scale) Do Ré Mi Fa Sol La Si Do.

A French word with the same sound is la scie (= a saw.) You can make un si with une sciea musical saw!

Finally, un if is a totally unrelated French word: it’s a tree, the common yew.

And now we’re done!

What did you learn today?

  • Si” can mean “If,” and follows some grammar rules.
  • Si” means “Yes” after a negative question or affirmation.
  • Si” also means “So much”, like “tellement.”
  • Si” is a musical note in French music.

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Join the conversation!

  • Thank you for this! When I have observed “si” in use #2, I have thought of it as a correction of a negative assumption (more than answering a negative question). par exemple : “Tu n’as jamais allé à Toulouse?” “Si si, je suis née à Toulouse!” “Vous n’avez pas encore mangé?” “Si, j’ai mangé il y a une heure.” 🙂

  • Thank you for this! When I have observed “si” in use #2, I have thought of it as a correction of a negative assumption (more than answering a negative question). par exemples : “Tu n’as jamais allé à Toulouse?” “Si si, je suis née à Toulouse!” “Vous n’avez pas encore mangé?” “Si, j’ai mangé il y a une heure.” 🙂

  • Comme ci comme ça …

    Ok ok ~ not the same si, but this is a very useful
    lesson on using this simple little word to help us
    get it right. In the past I’ve been known to get
    Si + Conditionnel wrong, which is one to look out
    for. And, of course, si means yes in both Spanish
    and Italian as well as in French when used in a
    certain way, so ….. il faut faire attention !

    Une super leçon Géraldine ~ merci merci 🙂

  • The first use of si for ‘if’ (present/present) is pretty unusual in English, at least I can’t think of a way to use it that works. “If I win, I will buy a car,” sounds correct. Let me think “if we are late the bus leaves without us” ehh, this is still kind of strange. “If we’re late the bus will leave…”. So in the English I speak, you couldn’t do that very often. But present/future works. It’s funny because quand je parle français, je souvent dis exactement comme ça, “si je gagne, je vais acheter une voiture”, so I’ve been wrong and probably equally awkward sounding!

    • “If + Present / Present” in English is the zero conditional (for rules, definitions and generalities) :

      For instance, “If the water gets to 100°C, it boils.” “If a rectangle has four sides of the same length, it’s a square.”

      In French, we use it that way too, but also for regular first conditional (In English = if + present / future, as you point out!).

      To be honest, that (already long) lesson leaves out (as of now) the “Si + présent, futur” in French, as in “Si tu viens, tu seras le premier” (If you come, you’ll be the first). For such a guess on the future though, we usually use the “futur simple” tense – and not the “futur proche”, for once!

      So “Si je gagne, je vais acheter une voiture” is actually OK too – but it sounds less awkward if you change it to either “Si je gagne, j’achète une voiture.” OR “Si je gagne, j’achèterai une voiture.” (simple future)

    • Present present use in English. If I win you pay. If I fall, it’s your fault and similar. What happens here in English is that the future is elided as unnecessary for understanding what is being said. In other words “if I win, you will be paying” is shortened by using the present and becomes, “If I win you pay”. Interestingly this shorter form is more contractual in English because of the use of the present, whereas the use of the future is more assertion and hope than contract. Greater brevity in a language often equates to higher certainly and clarity.

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