Past conditional formation

Level 3

The conditionnel passé (past conditional) is the French equivalent of 'would have [done].' It is a compound tense formed with a conditional auxiliary and a past participle.

How It Works

The past conditional allows you to talk about the past with a sense of 'what if.'

1. Formation
To form the past conditional, you use the conditional form of the auxiliary verb (either avoir or être) followed by the past participle of the main verb.

  • Avoir: j'aurais, tu aurais, il aurait, nous aurions, vous auriez, ils auraient
  • Être: je serais, tu serais, il serait, nous serions, vous seriez, ils seraient

2. Choosing the Auxiliary
The rules are the same as the passé composé:

  • Use être for reflexive verbs and 'DR MRS VANDERTRAMP' verbs (motion/change of state). However, only the handful of them that can take a direct object — monter, descendre, rentrer, sortir, retourner and passer — switch to avoir when they do (e.g., elle aurait sorti le chien). The others, like aller, venir, naître and rester, never take a direct object and always keep être.
  • Use avoir for everything else.

3. Agreement Rules
Just like other compound tenses, you must apply agreement rules:

  • Non-reflexive verbs with être: The past participle always agrees with the subject (e.g., elles seraient allées).
  • Reflexive verbs: The past participle agrees with the reflexive pronoun only if it is a direct object. If the pronoun is an indirect object, there is no agreement (e.g., elles se seraient parlé because you talk to someone).
  • Verbs with avoir: The past participle only agrees if there is a preceding direct object.

4. Negation
In negative sentences, just like other compound tenses, the negation wraps around the conjugated auxiliary verb, not the past participle (e.g., Je n'aurais pas fait cela). For reflexive verbs, the negation wraps around the reflexive pronoun and the auxiliary verb together (e.g., Je ne me serais pas réveillé(e)).

5. Key Functions

  • Hypotheticals: Often used with Si + plus-que-parfait to show what would have happened if conditions were different.
  • Regret/Reproach: Expressing disappointment. To say 'should have', use the past conditional of devoir + infinitive (e.g., j'aurais dû). To say 'could have', use pouvoir + infinitive (e.g., j'aurais pu).
  • Journalistic Allegation: Used by news outlets to report unconfirmed events (e.g., 'The thief reportedly stole...').
  • Future Perfect in the Past: Used in indirect discourse (reported speech) to express an action that would have been completed before another past action.

6. Literary Form
In formal literature, you may encounter the second form of the past conditional (conditionnel passé 2e forme), which is identical to the pluperfect subjunctive.

Examples (5)

  1. J'aurais voulu t'aider.

    I would have liked to help you.

    Word by Word: I would-have wanted to-you to-help.

    Uses the auxiliary 'avoir' in the conditional present + the past participle of 'vouloir' to express a past desire that wasn't fulfilled.

  2. Elle serait venue plus tôt si elle avait pu.

    She would have come earlier if she had been able to.

    Word by Word: She would-be come more early if she had could.

    Since 'venir' uses the auxiliary 'être', the past participle 'venue' must agree with the feminine subject 'elle'.

  3. Tu aurais dû me le dire !

    You should have told me!

    Word by Word: You would-have owed me it to-tell!

    The past conditional of 'devoir' (aurais dû) is the standard way to say 'should have' in French.

  4. L'avion aurait atterri avec deux heures de retard.

    The plane reportedly landed two hours late.

    Word by Word: The plane would-have landed with two hours of delay.

    This is the 'journalistic' use, indicating the information is not yet officially confirmed.

  5. Nous nous serions trompés de chemin.

    We would have taken the wrong path.

    Word by Word: We ourselves would-be mistaken of path.

    Reflexive verbs always use 'être'. Here, 'trompés' adds an 's' to agree with the plural subject 'nous'.

Common Mistakes

  • Using the conditional immediately after 'si' in a hypothetical clause.

    Si j'aurais su, je serais venu.
    Si j'avais su, je serais venu.

    In a 'si' clause expressing a past hypothesis, you must use the plus-que-parfait (avais su), not the conditional. The conditional only appears in the result clause.

  • Using 'avoir' instead of 'être' for reflexive verbs.

    Je m'aurais couché plus tôt.
    Je me serais couché plus tôt.

    All reflexive verbs must use 'être' as their auxiliary in the past conditional, just like in the passé composé.

  • Confusing the past conditional with the pluperfect (plus-que-parfait).

    J'avais mangé si j'avais eu faim.
    J'aurais mangé si j'avais eu faim.

    'J'avais mangé' means 'I had eaten' (a fact). 'J'aurais mangé' means 'I would have eaten' (a hypothesis). Use the conditional auxiliary for 'would have'.

How It Connects

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Past conditional formationLevel 3

Learn This First

The past conditional (conditionnel passé) is a compound tense. To form it, you must be able to conjugate the auxiliary verbs 'avoir' and 'être' in the present conditional and know how to pair them with the correct past participle, following the same auxiliary rules used in the passé composé.

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