What are the active and passive voices in French?

The active voice is a sentence structure in which the subject of the sentence performs the action. In other words, the focus of the sentence is on who performs the action.

Structure: Sujet + verbe + complément

The passive voice is a sentence structure in which the subject of the sentence is the recipient of the action.

Structure: Sujet + être (conjugated in the tense needed) + participe passé (+ par/de + agent )

A couple of things should be noted about the passive voice:

The participe passé must agree in gender and number with the subject.

The agent of the sentence - that is, the one doing the action to the subject - is introduced with par (or, less often, de).

Example:

La statue a été renversée par une rafale de vent. (The statue was blown over by a gust of wind.)

Note that only transitive verbs (verbs which take a direct object) can be used in the passive voice. Verbs which take à + indirect object (such as parler à or plaire à) cannot be used in the passive voice.

Examples of the difference between the active and passive voice:

Présent

Active: Le professeur corrige les devoirs.
Passive: Les devoirs sont corrigés par le professeur.

Active: Tout le monde la respecte.
Passive: Elle est respectée de tous.

Passé composé

Active: Marie a écrit une lettre.
Passive: Une lettre a été écrite par Marie.

Active: Le chat a mangé la souris.
Passive: La souris a été mangée par le chat.

It's worth noting that the passive voice, as outlined above, is less common in French than it is in English. That's because in French, you can always express a passive sentence structure using the pronoun on or the reflective pronoun se.

To understand how these pronouns are used in French to construct the passive voice, check out Lesson 38 of The Complete French Course.