Etymologically

si

Etymology and origin of the French word si

si1 if

Confidence
Established
Formation
Inherited
First attested
842, Serments de Strasbourg
Inherited from
Latin si via Old French
Ultimate origin
Latin (sī)

Pronunciation

Forms

si[1] Old French usually se (about 1050, earlier sed), s’ before a vowel, until the 16th century.[2][3] Se was eliminated in the 17th century, but survives in s'il.[2][3][4]

Etymology

The conjunction “si” is inherited from Old French se, inherited from Latin sī (“if; whenever”).[2][5][6][3] The Old French form “se” comes from popular *se (recorded in the 6th century), an alteration of “sī” after quid, which was used as a conjunction in Late Latin.[3][4] “Sed” “if” in the “Vie de saint Alexis” supports this.[3][2][4] “Si” appears early, in the Strasbourg Oaths, perhaps as a Latinism; it was the only form in Anglo-Norman and some western areas.[3]

Archaic Latin had “sei”.[2][7] No conditional conjunction is common to several Indo-European languages.[2] Ernout and Meillet held that “sī” and sīc (“so”) were originally one word meaning “in this case, so”.[2][6] Cognate with Italian se, Spanish si and Old Occitan si, Old Occitan se.[3]

Earliest recorded meaning

The Strasbourg Oaths (842) have si introducing a simple condition: Si Lodhuuigs sagrament… conservat “if Louis keeps the oath”.[8][2]

Semantic evolution

From the beginning si introduced a simple hypothesis (842); one fulfilled in the past is found in 1080, one excluded in the present at the end of the 12th century, and the potential about 1175.[2] Même si dates from about 1150, and concessive si (“though”) from the 12th century.[2] The noun un si “a condition” is found in sans si (13th century), avec un si (1718) and the proverb avec des si on mettrait Paris en bouteille (1787).[2] Si ce n'est dates from 1530, and sinon from the 15th century (Commynes).[2][3]

Timeline

  • 842 – Si in the Strasbourg Oaths.[8]
  • c. 1050 – Se in the Vie de saint Alexis.[2]
  • c. 1150 – Même si.[2]
  • 13th century – Sans si.[2]
  • 17th century – The form se disappears.[2]
  • 1787 – Avec des si on mettrait Paris en bouteille.[2]

Meanings

Conjunction

  1. if: introduces a condition or supposition: si tu viens, je reste.[9][4]
  2. Whether, if: introduces an indirect question: je me demande s'il viendra.[3][1]
  3. If only, what if: with the imperfect, expresses a wish or suggestion: si nous partions ?.[4]
  4. Though, while: marks a contrast: si l'un est riche, l'autre est pauvre.[2]

Noun

  1. (invariable) An if, a condition: avec des si….[2][9]

Word family

si2 so; yes

Confidence
Established
Formation
Inherited
First attested
842, Serments de Strasbourg
Inherited from
Latin sic via Old French
Ultimate origin
Latin (sīc)

Pronunciation

Forms

si[9]

Etymology

The adverb “si” is inherited from Old French si, inherited from Latin sīc (“so, thus”), also used in Latin for “so much” and in affirmation.[6][3][1] sic is a learned doublet.[1] The same Latin word gave the words for “yes” in Italian sì, Spanish sí and Portuguese sim.[3]

Earliest recorded meaning

The adverb is recorded from 842.[6][9]

Semantic evolution

In the Middle Ages si was common at the head of clauses in the sense “so, thus, yet”, as it still is in Walloon.[3] It is now an adversative affirmative particle, the “yes” used to contradict a negative statement, and an intensifier before an adjective or adverb, “so”.[3][9] Si fait “yes indeed” has become old-fashioned.[9][3] The compound aussi (12th century) contains the old pronoun al “other thing”.[3]

Meanings

Adverb

  1. yes: in answer to a negative question or statement: Tu ne viens pas ? — Si !.[9][1]
  2. so, such: il est si gentil, si bien que.[9][1]
  3. As (in comparisons): rien ne nous rend si grands qu'une grande douleur.[9]
  4. (obsolete) So, thus: si ferai.[9]

Word family

si3 the note B

Confidence
Established
Formation
Coinage
First attested
1646

Pronunciation

Forms

si m (invariable)[9]

Etymology

The note “si” was formed from the initials of “Sancte Iohannes” in the hymn to Saint John the Baptist, from which the names of the other notes (“ut”, “ré”, “mi”…) had been taken.[6][9]

Earliest recorded meaning

The Petit Robert dates it to 1646, the Grand Robert to the early 17th century.[9][6]

Meanings

Noun

  1. (music) The seventh note of the scale of C, B: si bémol.[6][9]

Word family

References

  1. ^ a b c d e f g h i Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n o p q r s Rey, Alain, ed. (1992), Dictionnaire historique de la langue française, Paris: Le Robert
  3. ^ a b c d e f g h i j k l m n o Bloch, Oscar; Wartburg, Walther von (1989), Dictionnaire étymologique de la langue française, 8th ed., Paris: Presses universitaires de France
  4. ^ a b c d e Guilbert, Louis; Lagane, René; Niobey, Georges, eds. (1971–1978; 1989), Grand Larousse de la langue française, Paris: Larousse
  5. ^ Wartburg, Walther von, et al. (1922–2002), Französisches Etymologisches Wörterbuch, 25 vols., Bonn / Leipzig / Basel: Klopp / Teubner / Zbinden, p. 11, 561a
  6. ^ a b c d e f g Rey, Alain, ed. (2005), Le Grand Robert de la langue française, electronic version, Paris: Le Robert
  7. ^ Littré, Émile (1873–1877), Dictionnaire de la langue française, 4 vols. and supplement, Paris: Hachette
  8. ^ a b Trésor de la langue française informatisé (2004), ATILF – CNRS & Université de Lorraine, atilf.fr/tlfi; electronic version of Imbs, Paul; Quemada, Bernard, eds. (1971–1994), Trésor de la langue française, Paris: CNRS / Gallimard
  9. ^ a b c d e f g h i j k l m n Rey-Debove, Josette; Rey, Alain, eds. (2007), Le Petit Robert de la langue française, Paris: Le Robert

Related etymologies

Cite this entry

“Si.” Etymologically, 18 Oct. 2026, etymologically.com/fr/si. Accessed 18 Oct. 2026.

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