Learn Hardcore French: La porte a été ouverte par Paul, mais la fenêtre est fermée par Marie. - The door was opened by Paul, but the window is closed by Marie.

subject + a form of être in the chosen tense + past participle of the main verb (+ optional par
- agent)
In passé composé, être itself is in passé composé: a été (has been)
Then add the main verb’s past participle: ouverte (from ouvrir) Meaning-wise, French passé composé can map to English was opened or has been opened depending on context.

Why do we see ouverte and fermée ending in -e?

Agreement. In the passive, the past participle agrees with the subject in gender and number because it functions like an adjective.

la porte (fem. sg.) → ouverte
la fenêtre (fem. sg.) → fermée If it were masculine: le portail a été ouvert. If plural: les portes ont été ouvertes.

Does the past participle always agree with the subject in the passive?

Yes. In passive constructions, the past participle agrees with the grammatical subject:

La lettre a été écrite (fem. sg.)
Les textes ont été corrigés (masc. pl.) This is different from many active-voice cases with avoir, where the participle does not agree with the subject.

What’s the nuance difference between a été fermée and est fermée?

a été fermée focuses on a completed action/event (was/has been closed).
est fermée usually describes a state (is closed). With an agent (par Marie), it can read as a present passive (the window is closed by Marie), often implying a general responsibility or the current resulting state due to her action. For a single completed action, a été fermée is clearer.

If I want to say “is being closed (right now),” is est fermée the best choice?

French lacks a dedicated progressive passive like English is being closed. More natural options:

Active: Marie est en train de fermer la fenêtre.
Passive (heavy but possible): La fenêtre est en train d’être fermée par Marie. Plain est fermée is usually read as a state or a general present passive, not a clear ongoing process.

Could I write La porte est ouverte par Paul instead of a été ouverte?

It’s grammatical (present passive), but in everyday French it often sounds stiff for a specific ongoing event. Prefer:

Active: Paul ouvre la porte (if it’s happening now)
Passive past for a completed action: La porte a été ouverte par Paul Present passive is fine for general truths: Ce musée est financé par la ville.

Why is par used and not de?

With action verbs and a true agent (the doer), use par:

ouverte par Paul, écrit par Victor Hugo De appears with certain participles/expressions (often feelings or perceptions) or when the relation isn’t an acting agent:
aimé de tous, connu de ses pairs, respecté de ses élèves Also, for instruments/means, use avec (or sometimes à), not par:
ouverte avec une clé

Can I omit the agent phrases (par Paul, par Marie)?

Yes. If the agent is unknown, irrelevant, or understood:

La porte a été ouverte.
La fenêtre est fermée.

How would I say the same idea in a more natural active voice?

Completed past for both: Paul a ouvert la porte, mais Marie a fermé la fenêtre.
Past then present: Paul a ouvert la porte, mais Marie ferme la fenêtre. French generally prefers active voice in everyday speech unless the passive is needed for focus or when the agent is unknown.

Where do I put par + agent in a passive sentence?

The default position is after the past participle:

La porte a été ouverte par Paul. Fronting par Paul is possible for emphasis or style but is marked/literary: Par Paul, la porte a été ouverte.

Could I say La porte s’est ouverte instead of a été ouverte par Paul?

Different meaning. La porte s’est ouverte (pronominal) means “the door opened (by itself/without specifying an agent).” … a été ouverte par Paul is passive and explicitly names the agent (Paul did the opening).

Is ouvrir irregular? What about fermer?

ouvrir is irregular. Key forms: present j’ouvre, tu ouvres, il ouvre, nous ouvrons, vous ouvrez, ils ouvrent; past participle ouvert (→ ouverte, ouverts, ouvertes by agreement).
fermer is regular (-er verb). Past participle fermé (→ fermée, fermés, fermées).

Are there pronunciation tips for this sentence?

La porte [la pɔʁt], a été [a ete] (both é like in “café”), ouverte [uvɛʁt]
la fenêtre [la fənɛtʁ], est fermée [ɛ fɛʁme]
par [paʁ], Paul [pɔl], Marie [maʁi] The final -e in fermée/ouverte isn’t pronounced; it just marks feminine agreement.

Is the comma before mais correct in French?

Yes. French typically places a comma before coordinating conjunctions like mais when they link two clauses: …, mais …. The comma in the sentence is standard.

If the nouns were plural or masculine, how would the forms change?

Masculine singular: Le portail a été ouvert par Paul.
Feminine plural: Les fenêtres sont fermées par Marie.
Masculine plural: Les volets ont été ouverts par Paul. Always make the past participle agree with the subject in passive constructions.