Choosing Between the Two Passives

Czech has two passives, and the single most useful skill at B2 is knowing which one to reach for. The reflexive passive uses the verb plus the clitic se (Tady se nekouří, "No smoking here"; Dům se staví, "A house is being built"). The participial passive uses být plus a passive participle (Dům byl postaven firmou Skanska, "The house was built by Skanska"). English collapses both into be + past participle, so English speakers default to the participial form — and that default is wrong most of the time in speech. This page gives you a decision tree that mirrors the way native speakers actually choose.

The quick answer

Reach for the reflexive passive (se) for general, agentless, conversational statements, signs, instructions, and ongoing processes. Reach for the participial passive (být + participle) for formal or written style, for emphasising a completed result, and above all when you need to name the agent. When in doubt in everyday speech, the reflexive passive is almost always the more natural choice.

Decision tree

Step 1: Is there a named or nameable agent?

If you want to say who did it, you almost always need the participial passive. The agent goes in the instrumental case, introduced by no preposition. The reflexive passive cannot take an explicit agent at all — *Dům se staví firmou is broken.

Notice the contrast: the moment "by an Italian company" appears, only the participial passive works. Drop the agent and the reflexive passive becomes the more natural everyday choice.

Step 2: Is it a sign, instruction, or general rule?

Public notices, prohibitions, and generic instructions overwhelmingly use the reflexive passive, often with no expressed subject at all. This shades into the impersonal se, but for now just note that the participial passive here sounds stiff and unidiomatic.

A sign reading Zde je zakázáno kouřit exists, but it is the wording of a formal regulation, not of an ordinary "no smoking" notice. For everyday prohibition, se nekouří wins.

Step 3: Process or result?

This is the deepest part of the distinction, and it lines up with aspect. An ongoing, imperfective process leans reflexive; a completed, perfective result leans participial. The reflexive passive happily describes something unfolding; the participial passive is at its best naming a finished state.

The pairing is not absolute — you can form a perfective reflexive passive (Dveře se otevřely) — but as a tendency it is strong: if you are reporting that something is finished and done, the participial form with a perfective verb is the crisp, natural choice. For why a perfective verb behaves this way, see aspect in the present.

Step 4: What register are you in?

Register is the tiebreaker. The participial passive is the register-marked form: it belongs to written, official, academic, and journalistic Czech. The reflexive passive is register-neutral — equally at home in conversation and in print. So in a contract, a news report, or an academic abstract, the participial passive is appropriate and expected. In a café conversation, it can sound like you are reading from a bylaw.

The last two say nearly the same thing, but the first is what a waiter tells a tourist and the second is what a school brochure prints. That register gap is the whole game.

Side-by-side summary

Why English speakers overuse the participial passive

In English, be + past participle is the only passive there is, and it is perfectly ordinary in speech ("the road is being repaired"). So English speakers transfer that habit and produce Silnice je opravována in casual conversation — which is grammatical but sounds like a press release. The reflexive passive has no English shape to anchor to, so it gets neglected. The corrective habit is simple: in speech, default to se, and only switch to the participial form when you genuinely need the agent or you are deliberately writing in a formal register.

For the structural mechanics of each form — how to build the participle, where the clitic se sits — see the reflexive passive and participial passive pages. This page is only about the choice between them.

Common Mistakes

Key Takeaways

• Need an agent? Only the participial passive (byl postaven firmou X) can name one.
• Sign, rule, or instruction? Use the reflexive passive (Tady se nekouří).
• Process vs result: ongoing/imperfective leans reflexive (staví se); completed/perfective leans participial (byl postaven).
• Register: participial = formal/written; reflexive = neutral, the default in speech.
• The English habit of using be + participle everywhere produces bureaucratic-sounding Czech; in conversation, reach for se first.