In short

The passive voice makes the thing acted on into the subject: it is built with an auxiliary verb - być (“to be”) or zostać (“to become / get”) - plus a passive participle (imiesłów przymiotnikowy bierny). The participle behaves like an adjective and agrees with the subject in gender, number, and virility. Which auxiliary you pick decides the meaning: zostać names a single completed event, while być describes a process or a resulting state. The doer, when named, follows the preposition przez + the accusative.

The rule

In an active sentence the subject does the action: Autor napisał list (The author wrote the letter). In the passive the object becomes the subject and the doer moves to the back after przez: List został napisany przez autora (The letter was written by the author).

Only transitive verbs (verbs that take a direct object in the accusative) form a passive.

The passive participle (imiesłów bierny)

The passive participle is made from the verb stem with one of three suffixes, then it takes adjective endings. The choice of suffix depends on the verb:

• -ny / -any - most verbs in -ać and many in -eć: pisać -> pisany, czytać -> czytany, widzieć -> widziany, dać -> dany, zbudować -> zbudowany.
• -ony - verbs in -ić / -yć and in -ść / -źć, usually with a consonant softening: robić -> robiony, kupić -> kupiony, prosić -> proszony (ś -> sz), nosić -> noszony, płacić -> płacony (ć -> c), przynieść -> przyniesiony, znaleźć -> znaleziony.
• -ty - verbs in -ąć / -nąć, short monosyllabic -ć verbs, and verbs in -uć / -rzeć: zamknąć -> zamknięty, wziąć -> wzięty, myć -> myty, zabić -> zabity, pić -> pity. A few are irregular: otworzyć -> otwarty.

być vs zostać - the aspect choice

This is the heart of the Polish passive.

• zostać + perfective participle = a single, completed, dynamic event (“got done”). Drzwi zostały otwarte. (The door was opened - it happened.) zostać is perfective, so it has no present tense - only past (został) and future (zostanie).
• być + imperfective participle = an ongoing or repeated process. List jest pisany. (The letter is being written.) Ulice są sprzątane co rano. (The streets are cleaned every morning.)
• być + perfective participle = the resulting state (“is in the condition of”). Drzwi są otwarte. (The door is open - a state, not the event of opening.)

Compare the two directly:

• Sklep został zamknięty o ósmej. = the act of closing happened at eight. (zostać, event)
• Sklep jest zamknięty. = the shop is (now) closed. (być, state)

The agent: przez + accusative

The doer is introduced by przez governing the accusative: dom został zbudowany przez robotników (the house was built by the workers - robotników accusative). The agent is often simply left out when it is unknown or unimportant: Samochód został skradziony. (The car was stolen.)

Agreement of the participle

Because the participle is adjectival, it agrees with the subject in gender and number, and in the plural it splits into virile (masculine-personal) and non-virile forms - with the softening typical of virile endings: -ny -> -ni, -ty -> -ci, -ony -> -eni.

• Student został zaproszony. (The student was invited - masc. sg.)
• Studentka została zaproszona. (fem. sg.)
• Studenci zostali zaproszeni. (virile pl. - note zaproszeni.)
• Studentki zostały zaproszone. (non-virile pl.)

Forms & patterns

Building the participle (three suffix types):

Participle agreement (verb zaprosić -> zaproszony):

Passive across tenses (subject list = the letter, masc. inanimate):

zostać conjugated (it has no present - perfective aspect):

Examples

Common mistakes

• List został napisana -> List został napisany - the participle must agree with list (masc.), not stay feminine.
• Studenci zostali zaproszone -> Studenci zostali zaproszeni - a virile (masculine-personal) plural subject needs the virile ending -eni.
• Dom został zbudowany przez robotnicy -> przez robotników - przez governs the accusative, so use robotników, not the nominative.
• Drzwi zostały otwarte teraz (as a state) -> Drzwi są otwarte - a present state uses być; zostać names the event and has no present.
• List jest napisany meaning “is being written” -> List jest pisany - the process needs the imperfective participle pisany; napisany gives the finished-state reading.
• Książka była pisana przez autora for a one-off completed act -> Książka została napisana przez autora - a single completed event takes zostać + perfective participle.

Tips

• Ask event or state? Event that happened once -> zostać; ongoing process or resulting condition -> być.
• The tense lives in the auxiliary: is it jest / był / będzie or został / zostanie? The participle only carries agreement.
• Match the participle to the subject exactly as you would an adjective (Lesson 11) - watch the virile plural: aresztowani, pobici, zaproszeni.
• Remember zostać is perfective, so it can never be a present tense. For “is being done” right now, use być + imperfective participle.
• The agent after przez is always accusative, even when the subject looks like it should be instrumental - the instrumental is for być + noun (Lesson 10), not for the passive doer.
• Polish, like many languages, often prefers the impersonal się-passive or the -no / -to form when the doer is generic (Lesson 49): Zbudowano most rather than a full participial passive.