I reckon this doesn't warrant an article (if they even accept articles on Danish?), but I felt like making a little guide / explanation as to how passive voice works in Danish, as I've been asked about this frequently. 

Despite Danish verbs being famous for being.. well.. "static" and only changing shape when used in different tenses, they do have an extra shape which does not exist in English. The following shapes are probably familiar to many: "At vaske"(infinitive), "Jeg vaskede"(preterite), "Jeg har/havde vasket" (past participle), "Vask!" (Imperative). But what about this last one: "Vaskes"?

Without getting into too many grammatical terms (I'm kind of an idiot), an active sentence looks like this:

Lars eats the rugbrød

While a passive sentence looks like this:

The rugbrød gets eaten (by Lars)

Whenever we have a passive sentence in Danish, there are two ways in which to construct it - only one of them contains the "vaskes" verb form. We'll begin with the most common one: Blive-passiv


In English, when a passive sentence is made it is often supported by the verb "to get" or "to be". Examples:
It got stolen - He was shot at 11 pm - The car was sold at the auction - He got put in his place

The Danish equivalent is the verb "at blive", meaning either to stay or to become (in this sense it should probably be understood as "to become").

Here are all five sentences (including the one with Lars) written in Danish with the verb "at blive":
Rugbrødet blev spist (af Lars)
Den blev stjålet
Han blev skudt kl. 23
Bilen blev solgt på auktionen
Han blev sat på plads

Whenever you wish to use present perfect or past perfect, the auxiliary verb is "at være" (to be)

Den er blevet stjålet (it has been) - Han er blevet skudt kl. 23 (he has been) - Han var blevet sat på plads (he had been)

Whenever you wish to express present tense OR future tense, use the present form of the verb: "bliver"
Rugbrødet bliver spist (the rugbrød gets eaten).
Here's the tricky part: The sentence above is ambiguous, and can be either present or future (it will by default be interpreted at present tense if no other clues are given). To emphasize that it is a future action, describe a time in which it will take place in the sentence:
Rugbrødet bliver spist i morgen / senere / om en time / snart
Another way to do this without having to specify a time is writing "vil blive":
Rugbrødet vil blive spist.

Now we arrive at the second part, where no auxiliary verb is used. The S-passiv:
The S-passiv is not easily translatable to English, but it can simply be explained as a passive voice without use of "at blive", which does not bind itself to any particular time. It is typically used either to replace the ambiguous present/future tense of "at blive", or in instructions/manuals in which time is neutral. It is constructed by adding -s to the infinitive verb. Here are some examples:

Dørene åbnes kl. 19 (The doors open at 7 pm) - (The doors do not open themselves - they will be opened by someone else, so passive voice)
Møblerne flyttes i dag (The furniture gets moved today)
Vandet koges, kartoflerne skrælles og kødet marineres (The water gets boiled, the potatoes get peeled and the meat gets marinated)
Der gøres rent efter opholdet (there will be cleaned / cleaning will happen after the stay)
Bilen bør vaskes (The car ought to be washed)
Hylden monteres ovenpå maleriet (The shelf gets mounted above the painting)