Passive infinitive after a modal
The passive infinitive (être + past participle) follows modal verbs like devoir, pouvoir, or vouloir to express what 'must be done', 'can be seen', or 'wants to be heard'.
How It Works
This construction is common in formal, administrative, and journalistic French. It allows the speaker to focus on the object of the action when the 'doer' is unknown or irrelevant.
1. Formation and Agreement
Unlike the active voice, the passive infinitive always uses être. Because the auxiliary is être, the past participle must agree with the subject:
- La lettre doit être écrite. (The letter must be written.)
- Les documents peuvent être envoyés. (The documents can be sent.)
2. Common Verbs
The most common verbs used to trigger this construction are:
3. Pronoun Placement
If you use an object pronoun (like y or en), it is placed immediately before the infinitive être, not before the modal verb.
Example: Cela doit y être déposé. (That must be left there.)
4. Register and Usage
While English uses the passive voice frequently, French often prefers the on construction or reflexive verbs in casual speech. The passive infinitive is best suited for formal writing or giving authoritative instructions.
Examples (6)
- Ce document doit être signé par le directeur.
This document must be signed by the director.
Word by Word: This document must to be signed by the director.
Here, 'doit' (must) is followed by the passive infinitive 'être signé'. The focus is on the document.
- Les résultats peuvent être consultés en ligne dès demain.
The results can be viewed online starting tomorrow.
Word by Word: The results can to be consulted in line from tomorrow.
Note the plural agreement 'consultés' matching the masculine plural subject 'les résultats'.
- Il faut être inscrit pour participer à l'événement.
It is necessary to be registered to participate in the event.
Word by Word: It must to be registered for to participate at the event.
The impersonal verb 'il faut' is frequently used with a passive infinitive to state requirements.
- Cette règle devrait être respectée par tous les usagers.
This rule should be respected by all users.
Word by Word: This rule should to be respected by all the users.
The conditional form of 'devoir' (devrait) is used here with the passive infinitive for a polite or general recommendation.
- Je veux être entendu.
I want to be heard.
Word by Word: I want to be heard.
Even 'vouloir' can take a passive infinitive when expressing a desire for an action to be performed on oneself.
- La décision doit être prise rapidement.
The decision must be made quickly.
Word by Word: The decision must to be taken quickly.
The past participle 'prise' agrees with the feminine singular subject 'la décision'.
Common Mistakes
Forgetting to agree the past participle with the subject.
La lettre doit être écrit.La lettre doit être écrite.In the passive voice, the past participle always agrees with the subject because the auxiliary is 'être'.
Adding a preposition like 'de' or 'à' between the modal and 'être'.
Je veux d'être respecté.Je veux être respecté.Modal verbs like 'vouloir', 'pouvoir', and 'devoir' are followed directly by the infinitive without any preposition.
Using the active infinitive when the passive is required.
Ce travail doit finir.Ce travail doit être fini.If the subject (the work) isn't doing the finishing, you must use the passive 'être fini'.
How It Connects
Learn This First
To understand the passive infinitive after a modal, you must first know how to form the passive voice using 'être' and a past participle. You also need to understand that modal verbs in French are followed directly by an infinitive, and that the past participle in a passive structure must agree in gender and number with the subject.
- Passive with etre + past participle
The passive infinitive is formed using the same components as the passive voice (être + past participle).
Level 3 - Verbs linked directly to an infinitive
Modal verbs (devoir, pouvoir, vouloir) belong to the category of verbs that govern a direct infinitive without a preposition.
Level 2
Related Patterns
- Formal register favors the passive
Explains why the passive infinitive is more common in professional or journalistic contexts than in speech.
Level 5 - se + VerbMiddle Voice with a Reflexive Verb
A common alternative to the passive voice in casual French, often used instead of the passive infinitive.
Level 4 - Agreement in etre-conjugated past tenses
Provides the specific rules for how to change the ending of the past participle to match the subject.
Level 2 - devoir (obligation / probabilité)Devoir: Obligation or Probability
The most common modal verb used in this construction to express necessity.
Level 2
Learn Next
Patterns that build on this one.
Practice Passive infinitive after a modal in Bubblegum
Poppy, your AI tutor, writes French lessons at your level. Tap any grammar point in a lesson to see its full explanation.
