Yes in French: oui, si and non, and when to use each

Yes in French is oui, and no is non. When the question is phrased in the negative, such as “Don’t you know him?”, you say yes with si, not oui [1][2][4]. This page gives the words in a table, then each one in turn, with the dictionary entries behind them. For more spoken practice, see French speaking practice and French pronunciation practice.

Source: Dictionnaire de l’Académie française, 9th edition (2024), entries oui, si and non, opened 22 October 2026 [1][2][3].

How do you say yes in French?

You say oui. The Académie française defines it as the word that answers yes to a question asked or implied, and it can stand as a whole sentence or open one [1]. Its examples are “Le sait-il ? – Oui.” and “Sont-ils là ? – Oui, ils sont arrivés à trois heures.” (Does he know? – Yes. Are they there? – Yes, they arrived at three o’clock.) [1].

Larousse describes it the same way: oui expresses a positive answer to a question that is not phrased in the negative, and it can be strengthened with certes, bien sûr or mais [4]. Its French-English entry translates “tu en veux ? – oui, s’il te plaît” as “do you want some? – (yes) please” [5].

To strengthen oui, the Académie lists doubling it or adding a word: oui, oui, bien sûr que oui, mais oui ! and oui, cent fois oui ! [1]. It adds a note that oui should not be replaced by other adverbs such as absolument or tout à fait [1].

How do we say yes in French when the question is negative?

You say si. The Académie française says si answers yes to a question phrased in the negative, or contradicts a negative statement [2]. Its examples are “N’avez-vous pas été à cet endroit ? – Si.” and “Tu n’as pas rangé ta chambre. – Si, je viens de le faire.” (You haven’t tidied your room. – Yes, I just did.) [2].

The entry for oui says the same from the other side: to answer yes to a negative question, one ordinarily uses si [1]. Larousse’s note on oui is also direct: the affirmative answer to a negative question is not oui but si [4]. Its French-English entry translates “ce n’est pas fermé ? – si” as “isn’t it closed? – yes (it is)” [7].

To press the point, the Académie gives mais si, bien sûr que si and que si, oh que si [2]. It also lists si fait as an old-fashioned way to affirm the opposite of what someone said [2].

How do you say no in French?

You say non. The Académie française defines it as the word that answers no, the opposite of oui, and it can form a sentence or open one [3]. Its example is “Le voulez-vous ? – Non.” (Do you want it? – No.) [3]. Larousse gives the same first sense: a negative answer, as in “Viendrez-vous ? – Non” [10].

Larousse translates “non merci !” as “no, thank you!” and “mais non !” as “no!, absolutely not!” [6]. For emphasis the Académie lists non, non et non, certes non, bien sûr que non and mais non ! [3].

Non is also used for a short answer inside a longer sentence. The Académie’s example is “Il dit que non” (he says no) [3]. In the same way, il a répondu que oui uses oui for “he said yes” [1].

At the end of a sentence, a questioning non ? is a familiar way to ask “right?” The Académie’s example is “J’ai raison, non ?” [3], and Larousse translates a similar sentence as “wasn’t he?” or “is it?” depending on the sentence [6].

What is the French of “yes” in casual speech?

In casual speech people say ouais. Larousse’s French-English dictionary labels it familiar and translates it as “yeah” [8]. Le Robert’s online thesaurus lists it as a familiar interjection meaning oui, and defines it as familiar and sometimes ironic, sceptical or careless [9].

Treat ouais like English “yeah”: fine with friends, less fitting in a formal email or an interview. That register advice is a general observation, not a dictionary finding.

How do you say yes or no to something, or both?

To say yes to something, the Académie gives dire oui à quelque chose: to approve it or consent to it [1]. Larousse translates “le nucléaire oui, mais pas à n’importe quel prix !” as “yes to nuclear energy, but not at any cost!” [5].

To say “partly”, use oui et non. The Académie defines it as “in part only”, with the example “C’est bien ce qu’il voulait ? – Oui et non.” [1]. To say you will not commit, the Académie gives ne dire ni oui ni non [1][3]. Larousse has a French-English entry for it too: “elle n’a dit ni oui ni non” is “she didn’t say either yes or no” [5].

Both words are also nouns that do not change in the plural: des oui, des non [4][10]. The Académie’s example is the count at a referendum: “les non l’ont emporté sur les oui” [3].

How is oui pronounced, and can you join it to the word before?

Larousse transcribes oui as [wi] [5]. The Académie notes that neither liaison nor elision happens before this word [1].

Larousse adds a spoken-French detail. In careful speech the word before oui is never elided, as in je crois que oui. In everyday speech it often is, as in je crois qu’oui, but that elision is not written except when transcribing speech or in a dictionary example [4]. For wider sound work, see French pronunciation practice. For Québec words that differ from France, see English to Quebec French.

How can you practise yes and no?

Make the pair a habit by answering real questions aloud. A general suggestion, not a sourced method: write five questions in the positive and five in the negative, and answer each one out loud with oui, si or non. The negative ones are where English speakers tend to slip, because English has one word for both. If you want to hear from Lingwell when it opens, join the waitlist.

Common mistakes

• Answering a negative question with oui. Tu n’as pas faim ? asks about hunger in the negative. If you are hungry, the Académie and Larousse say to answer si [1][2][4].
• Using si for every yes. As a plain answer, si is for a negative question or a negative statement. For other questions, use oui [1][2].
• Pronouncing the n in non as a full “n”. The Larousse transcription [nɔ̃] marks a nasal vowel [6].
• Eliding in writing. Larousse says the elision in “je crois qu’oui” is not written outside transcriptions of speech and dictionary examples [4].
• Using ouais everywhere. Larousse and Le Robert both label it familiar [8][9].
• Relying on a vocabulary page from a blog, including this one. Dictionary entries change between editions. Compare each entry’s edition and date with the date at the top of this page.

See also: French question words and goodbye in French.

See also: French negation.

Sources