Expressing time: simultaneity and posteriority when, tant que, dès que

Exprimer le temps: la simultanéité et la posteriorité quand, tant que, dès que


Situe deux actions ensemble ou l’une après l’autre avec quand, tant que, dès que, une fois que.

(Places two actions at the same time or one after the other with quand, tant que, dès que, une fois que.)

What you are doing here: linking two actions in time

You are learning temporal links to say:

  • simultaneity / duration (two things happen at the same time)
  • posteriority (one thing happens after another, often immediately)

These connectors are very common in professional French: reports, processes, cause-and-effect explanations.

Simultanéité (at the same time / for as long as)

Connector Core meaning Typical use
Chaque fois que every time repeated correlation
Tant que as long as / while duration + “condition that remains true”
Aussi longtemps que for as long as emphasis on length of time
Au fur et à mesure que as / gradually as parallel evolution (step by step)

Key B2 reflex: with these duration connectors, French normally uses indicative in the time clause.

  • Present for general truths / habits: Tant que les taux restent bas…
  • Imperfect for background in the past: Tant que les taux restaient bas…

Posteriority (after / as soon as / once)

Connector Speed Nuance
Dès que immediate the moment X happens, Y starts
Une fois que after completion focus on “X is done/validated”
À peine + participe passé very immediate “hardly… when…” (often formal/written)
Dès que… et que… trigger combo two conditions must occur to trigger Y

The most common trap: no future after these time connectors

English often uses future: “as soon as he will arrive…”. French does not.

Use the indicative tense that fits the timeline (present, passé composé, imparfait, etc.), but avoid the future in the subordinate time clause.

  • Correct: Dès que le fournisseur livre, on lance la production.
  • Wrong: Dès que le fournisseur livrera, on lance la production.

For the future meaning, French typically puts the future in the main clause:

  • Dès que le fournisseur livre, nous lancerons la production.
  • Une fois que l’audit a été validé, l’usine pourra réduire ses coûts.

Gérondif: “En + participe présent” (a practical way to show “by/while doing”)

Form: en + verb in -ant

  • réduire → en réduisant
  • optimiser → en optimisant

Main uses you need:

  • Simultaneous action: Elle répond aux clients en gérant les urgences.
  • Means / method (often like “by”): On améliore la marge en réduisant les coûts fixes.

Quick check: the subject is usually the same for both actions.

  • OK: L’usine reste compétitive en réduisant les coûts. (same actor: the factory/company)
  • Avoid: En réduisant les coûts, la compétitivité augmente. (the “doer” is unclear)

Choosing the right connector: a fast decision guide

  1. Is it repeated?Chaque fois que
  2. Is it “true during a period”?Tant que / Aussi longtemps que
  3. Is it a gradual change?Au fur et à mesure que
  4. Does Y start right after X?Dès que
  5. Does X need to be completed first?Une fois que

Self-check (before you speak or write)

  • Did I pick duration (tant que) vs trigger (dès que)?
  • Did I avoid future tense in the time clause after dès que / tant que / une fois que?
  • If I used en + -ant, is the doer clearly the same?
Simultanéité (Simultaneity)Exemple (Example)
Chaque fois que (Each time)Chaque fois que la production augmente, l’emploi progresse. (Each time production increases, employment rises.)
Tant que (As long as)Tant que l’investissement continue, la croissance reste solide. (As long as investment continues, growth remains strong.)
Aussi longtemps queLa crise continuera aussi longtemps que personne ne se manifeste. (The crisis will continue as long as no one comes forward.)
Au fur et à mesure que (As / as and when)La chaîne change au fur et à mesure que la demande évolue. (The supply chain changes as demand evolves.)
Postériorité 
GérondifEn réduisant les coûts, l’usine reste compétitive. (By reducing costs, the factory remains competitive.)
Une fois que (Once)Une fois que la matière est transformée, elle part. (Once the material has been processed, it is shipped.)
Dès que (As soon as)Dès que la demande augmente, l’industrie recrute. (As soon as demand increases, industry hires.)
A peine + participe (Hardly + participle)A peine lancé, le projet attire des investisseurs. (Hardly launched, the project attracts investors.)
Dès que… et que… (As soon as… and…)Dès que les prix montent et que l’offre baisse, on réagit. (As soon as prices rise and supply falls, we react.)

Exercise 1: Multiple choice

Instruction: Choose the correct answer

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1. _____ les taux d’intérêt restent bas, l’investissement dans le secteur industriel se maintient.

_____ interest rates remain low, investment in the industrial sector is maintained.

2. _____ la matière première arrive, on lance la transformation sur la chaîne d’approvisionnement.

_____ the raw material arrives, we start processing in the supply chain.

3. _____ l’audit énergétique aura été validé, l’usine pourra réduire ses coûts sans délocaliser.

_____ the energy audit has been approved, the factory will be able to reduce its costs without relocating.

4. _____ la balance commerciale se dégrade, le ministère annonce souvent des mesures de soutien à l’export.

_____ the trade balance deteriorates, the ministry often announces measures to support exports.

Exercise 2: Rewrite the phrases

Instruction: Rewrite each sentence by introducing the indicated temporal subordinate clause (simultaneity or anteriority/posteriority). Example: He calls me. I leave the office. → Whenever I leave the office, he calls me.

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  1. Hint Hint (Une fois que) Je signe le bon de livraison. Le transporteur peut charger la marchandise.
    ⇒ ____________________________________________________________________________________________________ Example
    Une fois que j’ai signé le bon de livraison, le transporteur peut charger la marchandise.
    (Once I have signed the delivery note, the carrier can load the goods.)
  2. Hint Hint (Dès que) Le service qualité valide le lot. La production redémarre.
    ⇒ ____________________________________________________________________________________________________ Example
    Dès que le service qualité valide le lot, la production redémarre.
    (As soon as the quality department validates the batch, production restarts.)
  3. Hint Hint (Chaque fois que) Le chef d’atelier fait une pause. L’équipe en profite pour poser des questions.
    ⇒ ____________________________________________________________________________________________________ Example
    Chaque fois que le chef d’atelier fait une pause, l’équipe en profite pour poser des questions.
    (Every time the workshop manager takes a break, the team takes the opportunity to ask questions.)
  4. Hint Hint (Tant que) L’approvisionnement suit le planning. Le chantier avance sans retard.
    ⇒ ____________________________________________________________________________________________________ Example
    Tant que l’approvisionnement suit le planning, le chantier avance sans retard.
    (As long as supply follows the schedule, the construction site progresses without delay.)

Exercise 3: Multiple Choice

Instruction: Choose the correct sentence.

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1.
After “as long as,” we do not use the future for a condition that lasts; we generally use the indicative (present tense) in the subordinate clause.
2.
After “as soon as,” we avoid the future in the temporal subordinate clause in everyday French; we use the present indicative instead (or another appropriate indicative tense).

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Marco De Faria

Master in Foreign Languages

University of Poitiers

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France


Last Updated:

Saturday, 11/07/2026 06:01