How do you form the passive voice in French?

Take the verb être in whatever tense you need and add the past participle of the main verb, and make the participle agree with the subject in gender and number, exactly like an adjective. The tense lives in être, not in the participle: la lettre est écrite (present), la lettre a été écrite (perfect), la lettre sera écrite (future), la lettre serait écrite (conditional). Because être carries the agreement, a feminine plural subject pulls a feminine plural participle: les maisons ont été construites. The person who does the action, the agent, is added with par if you want to name them: la lettre a été écrite par Marie.

Why does French avoid the passive and use 'on' instead?

French finds the passive heavy and prefers an active sentence wherever it can. The commonest dodge is the pronoun on, which means 'one / people / they / someone' and lets you keep an active verb when the doer is vague or unknown. English reaches for the passive in exactly these cases, so the two languages line up neatly: on m'a volé mon sac is literally 'someone stole my bag from me', but it translates 'my bag was stolen'. Likewise on parle français ici is 'French is spoken here'. Whenever the agent is unimportant or unknown, on + active verb is more natural in French than a full passive.

Why can't you say 'I was given a book' as a passive in French?

Because French can only make a passive subject out of the direct object of a verb, never the indirect object. In 'someone gave a book to me', the direct object is 'a book' and the indirect object is 'me'. English happily promotes the indirect object to subject - 'I was given a book' - but French refuses. You cannot say 'je sais été donné un livre' or anything like it. The fix is on: on m'a donné un livre (literally 'someone gave me a book'). The same applies to on m'a dit que (I was told that) and on m'a demandé de (I was asked to). If the English passive starts with a person who was the receiver, switch to on.

The French Passive Voice

Most of the time French sentences are active: a subject does something to an object. Les ouvriers ont construit les maisons - the workers built the houses. The passive flips that round so the thing acted upon becomes the subject: les maisons ont été construites - the houses were built. The action is the same; the spotlight has moved.

English loves the passive and uses it constantly, often to avoid naming who did something. French knows the construction but treats it with suspicion, and it has two favourite ways of avoiding it. So this page has two jobs: first, how to build the passive when you genuinely want it; second, and just as important, the structures French reaches for instead.

How the passive is built: être + past participle

The French passive is the verb être plus a past participle, and the participle agrees with the subject in gender and number, exactly like an adjective. This is the single most important point: the participle behaves like an adjective hung off être, so it must agree.

La lettre est écrite. (The letter is written.)
La maison est construite. (The house is built.)
Les lettres sont écrites. (The letters are written.) - feminine plural, so écrites.
Les maisons sont construites. (The houses are built.) - feminine plural, so construites.

Note the agreement working: écrite for a feminine singular subject, écrites for a feminine plural, construites for les maisons. A masculine plural subject would take -s alone: les livres sont vendus (the books are sold).

The tense lives in être, not the participle

To change the tense of a passive, you change the tense of être and leave the participle alone. This is where learners wobble, because the participle of the main verb sits next to a second participle (été) in the compound tenses. Work through one verb across the tenses:

Tense	French passive	English
Present	la lettre est écrite	the letter is written
Perfect	la lettre a été écrite	the letter has been written
Imperfect	la lettre était écrite	the letter was being written
Future	la lettre sera écrite	the letter will be written
Conditional	la lettre serait écrite	the letter would be written

In the perfect, a été écrite has two participles: été (from être, invariable here) and écrite (agreeing with la lettre). The plural is les lettres ont été écrites - ont for the plural auxiliary, écrites for the agreement. Get both right and the rest follows.

Les maisons ont été construites en 1900. (The houses were built in 1900.)
Le pont sera terminé l'année prochaine. (The bridge will be finished next year.)
Ces tableaux seraient vendus aux enchères. (These paintings would be sold at auction.)

The agent: par, and de for emotion and description

If you want to name who does the action - the agent - you bring them in with par (by):

La lettre a été écrite par Marie. (The letter was written by Marie.)
Le voleur a été arrêté par la police. (The thief was arrested by the police.)
Ces maisons ont été construites par une grande entreprise. (These houses were built by a large company.)

There is an exception worth knowing. After verbs of emotion, attitude or description - states rather than physical actions - the agent comes in with de, not par:

Il est respecté de tous. (He is respected by everyone.)
Elle est aimée de ses élèves. (She is loved by her pupils.)
Le sommet était couvert de neige. (The summit was covered with snow.)
Cette région est connue de tout le monde. (This region is known to everyone.)

The rough rule: a one-off physical action takes par (arrêté par la police); a continuous state of feeling or appearance takes de (respecté de tous, couvert de neige).

French prefers on: the everyday alternative

Here is the cultural difference. English happily writes French is spoken here or my bag was stolen with no agent, because the passive is the natural way to hide an unknown or unimportant doer. French finds the full passive heavy and reaches instead for on - a vague subject meaning "one / people / they / someone" - with an active verb:

On parle français ici. (French is spoken here.) - literally "one speaks French here".
On m'a volé mon sac. (My bag was stolen.) - literally "someone stole my bag from me".
On a fermé le magasin. (The shop has been closed.)
On construit beaucoup de maisons dans cette région. (Many houses are being built in this region.)

Whenever the English passive has no agent, or an agent you would only introduce with a vague "by someone", on + active verb is almost always the better French. Reserve the true être passive for when you genuinely want to name the agent with par, or for a formal, written register.

The pronominal passive: ça ne se dit pas

French has a second dodge: the pronominal (reflexive) passive, where a normally active verb is made reflexive with se and given a passive sense. It works best with things, customs and general truths:

Ça ne se dit pas. (That isn't said. / You don't say that.)
Le vin rouge se sert à température ambiante. (Red wine is served at room temperature.)
Le vin blanc se sert frais. (White wine is served chilled.)
Ce livre se vend très bien. (This book sells very well. / is sold very well.)
Le français se parle dans de nombreux pays. (French is spoken in many countries.)

The verb still agrees with its grammatical subject (ces livres se vendent bien), but no agent is ever named - that is the whole point. The pronominal passive is the natural French for general statements about how things are done.

The trap: English passives built on an indirect object

This is the rule that catches everyone, so hold it carefully. French can only turn the direct object of a verb into a passive subject. It can never promote an indirect object.

Take donner quelque chose à quelqu'un (to give something to someone). The direct object is quelque chose; the person is the indirect object (à quelqu'un). English cheerfully makes the person the subject:

I was given a book.
She was told the news.
We were asked to wait.

French cannot do this. There is no way to say "je sais été donné un livre". The book can become a passive subject (un livre m'a été donné, rather formal), but I / she / we cannot, because they are the indirect object. The everyday solution is on:

On m'a donné un livre. (I was given a book.)
On lui a annoncé la nouvelle. (She was told the news.)
On nous a demandé d'attendre. (We were asked to wait.)

If your English passive starts with a person who received the action, do not even try to build a French passive. Switch straight to on + active verb.

Worked examples

La voiture a été réparée hier. (The car was repaired yesterday.) - perfect passive, réparée agrees with la voiture.
Les fenêtres ont été cassées pendant la tempête. (The windows were broken during the storm.) - feminine plural, cassées.
Ce roman a été traduit en vingt langues. (This novel has been translated into twenty languages.) - masculine singular, traduit, no extra ending.
Le président est respecté de tous. (The president is respected by everyone.) - state of feeling, agent with de.
On a annulé le concert. (The concert was cancelled.) - on preferred over a full passive, no agent.
Ce plat se mange froid. (This dish is eaten cold.) - pronominal passive, a general custom.
On m'a offert des fleurs. (I was given flowers.) - indirect-object passive in English, so on in French.

Common mistakes English speakers make

The first and biggest error is forgetting the agreement: it is la lettre a été écrite, not "la lettre a été écrit" - the participle is an adjective hung off être and must match the subject. The second is putting the tense on the wrong word: the tense lives in être (sera écrite, était écrite), never in the main participle. The third is over-using the passive because it feels natural in English - where English drops the agent, French almost always prefers on, so prefer on parle français ici over a literal le français est parlé ici in speech. The fourth, and the one that catches even strong learners, is trying to make an indirect object the subject: "I was given a book" cannot become a French passive, so you must say on m'a donné un livre. Finally, watch the agent preposition: physical actions take par (arrêté par la police) but verbs of feeling and description take de (aimé de tous, couvert de neige).