Dörren öppnas inte utan nyckel.

not

Breakdown of Dörren öppnas inte utan nyckel.

• utan: without
• dörren: the door
• nyckeln: the key

Questions & Answers about Dörren öppnas inte utan nyckel.

Why is it öppnas and not öppnar?

Öppnar is active voice and normally needs an object: someone opens something (e.g., Vakten öppnar dörren). With Dörren as the subject, you want the door as the thing being opened, so Swedish uses the passive/middle form öppnas: Dörren öppnas = “The door is opened/opens (is openable).”
Saying Dörren öppnar would incorrectly mean “The door opens (something).”

What does the -s in öppnas mean?

The -s marks the s‑passive (present tense here). It often has a passive or “middle voice” sense: general possibility/habit or events without naming an agent.
Forms: öppna – öppnar – öppnades/öppnas – har öppnats.

Does Dörren öppnas inte mean “cannot be opened” or just “is not opened”?

Both readings are possible. In contexts like this (with a condition: utan nyckel), Swedish s‑passive commonly conveys inability: “can’t be opened.” It can also be a habitual statement (“isn’t opened [in such circumstances]”).

Can I say Dörren kan inte öppnas utan nyckel instead?

Yes. It’s fully idiomatic and makes the “ability” part explicit.
Nuance:

• öppnas inte = concise, often used for rules/properties.
• kan inte öppnas = explicit impossibility, slightly more formal.