Conditionnel passé

J'aurais dû t'appeler hier.I should have called you yesterday.

The conditionnel passé is French's way of saying "would have." Most often that means looking back at something that didn't happen, or reporting a past fact you're not fully vouching for — but, as you'll see below, it also has a plain, non-hypothetical use in reported speech. It reuses the conditionnel présent you already know, just with the auxiliary pushed one step further to add the past participle.

Quick shortcut: conditionnel présent of avoir or être + past participle.

How it's formed

The auxiliary verb (avoir or être) goes in the conditionnel présent, followed by the past participle — the same participle you already use for the passé composé and the plus-que-parfait.

The same rules you already know from the passé composé and the plus-que-parfait still apply:

• Which auxiliary? The same verb takes the same auxiliary it always does — a small group of verbs (mostly movement or change of state) plus all pronominal verbs use être; most others use avoir.
• Agreement with être: the participle agrees with the subject — elle serait partie, ils seraient partis.
• Agreement with avoir: the participle normally doesn't change (elle aurait mangé), but agrees with a preceding direct object when there is one.

Pronominal verbs use être too, but agreement isn't automatic there — it depends on whether the pronoun se is acting as a direct object. When it is, the participle agrees with it, just like tu in tu te serais reposé(e) (you would have rested) or ils in ils se seraient rencontrés (they would have met). But when the sentence already has its own direct object, se becomes an indirect object instead and the participle stays unchanged: elle se serait lavé les mains (she would have washed her hands), not lavée.

Regret and reproach

The most common everyday use: looking back at something and wishing it had gone differently, either about yourself (regret) or about someone else (reproach).

• J'aurais dû l'écouter. (I should have listened to her.)
• Tu aurais pu me le dire ! (You could have told me!)
• Il n'aurait pas fallu partir si tôt. (There was no need to leave so early.)
• Vous auriez dû réserver à l'avance. (You should have booked in advance.)

Compare this with plain devrais/devriez — the conditionnel présent of devoir gives present-day advice ("you should rest"), while aurais dû looks back at a missed opportunity that's now in the past ("you should have rested" — and didn't).

Unconfirmed past information

News reports and journalism use the conditionnel passé to report a past fact the speaker isn't fully vouching for — the source is a claim, a rumor, or an ongoing investigation, not confirmed fact. English usually reaches for "reportedly" or "allegedly" instead of a special verb form:

• Le suspect aurait pris la fuite avant l'arrivée de la police. (The suspect reportedly fled before the police arrived.)
• Selon des témoins, l'accident se serait produit vers minuit. (According to witnesses, the accident reportedly happened around midnight.)

This use is mostly confined to formal, written reporting — not something to reach for in everyday conversation.

The "if I had known..." pattern

The conditionnel passé also completes the classic "if I had known, I would have..." sentence, pairing with a si-clause in the plus-que-parfait:

Si j'avais su, je serais venu(e) plus tôt. (If I had known, I would have come earlier.)

In this pattern, the si-clause takes the plus-que-parfait, never the conditionnel — the same way a si + imparfait clause never takes the conditionnel présent in the pattern you already know. This particular pairing — talking about an imaginary past that didn't happen — has its own full set of rules, covered in a dedicated lesson on si-clauses with the plus-que-parfait; here it's enough to recognize the conditionnel passé playing its usual role in the main clause.

In reported speech: a plain tense shift, not a regret

Reported speech shifts a futur simple back into the conditionnel présent once the reporting verb is in the past (Il a dit qu'il viendrait). The same shift applies to the futur antérieur: it becomes the conditionnel passé, with no hint of regret or doubt involved at all — just a future-in-the-past that was already going to be finished by some point.

Elle a dit : « J'aurai fini avant midi. » → Elle a dit qu'elle aurait fini avant midi. (She said she would have finished before noon.)

Here the conditionnel passé is doing the same job as any backshifted tense in reported speech — nothing about the original statement was hypothetical or uncertain.

Common mistakes

• ❌ J'aurais du appeler. → ✅ J'aurais dû appeler. (the circumflex on dû isn't optional — it distinguishes the past participle of devoir from the partitive article du)
• ❌ Elle aurait allée au marché. → ✅ Elle serait allée au marché. (aller takes être, not avoir)
• ❌ Elle serait allé au marché. → ✅ Elle serait allée au marché. (with être, the participle agrees with the subject — here, feminine)
• ❌ Je devrais l'écouter hier. → ✅ J'aurais dû l'écouter hier. (the conditionnel présent of devoir gives present-day advice; it can't describe an obligation already missed at a specific point in the past like hier — that calls for the conditionnel passé instead)

Quick check

Put the verb in brackets into the conditionnel passé.

1. Tu (devoir) ____ me prévenir.
2. Nous (vouloir) ____ venir, mais nous étions malades.
3. Selon la police, les voleurs (partir) ____ par la fenêtre.
4. Si elle avait su, elle (rester) ____ chez elle.

Key takeaways

• Conditionnel passé = conditionnel présent of avoir or être + past participle — built like the plus-que-parfait, with the conditionnel present instead of the imparfait.
• Its everyday use is regret and reproach: j'aurais dû, tu aurais pu, contrasted with plain devrais/pourrais for present-day advice.
• Formal reporting uses it for unconfirmed past information — a claim the speaker isn't fully vouching for (le suspect aurait fui).
• It completes the "if I had known, I would have..." pattern, pairing with a si-clause in the plus-que-parfait.
• In reported speech, it's also a plain backshift of the futur antérieur — no regret or doubt involved, just a future-in-the-past that was already going to be finished.
• Auxiliary choice and agreement follow the same rules as the passé composé and plus-que-parfait, including the special rule for pronominal verbs.