Getrunken wird hingegen nur etwa alle zwei Tage.
I'm confused by the above sentence I came across elsewhere. None of the grammatical rules I know seem to explain it. The word "getrunken" could either be a verb (in past-participle form) or an adjective. But where is the subject of the sentence?
Presumably this sentence is translated as, "On the other hand, there is drinking about every two days."
Can a native German speaker or language expert kindly explain.
I think SIgridKahl1 really knocked this one out of the park, and as I am neither a native German speaker, nor a language expert, I thought I would just provide some links to the two main points of confusion I believe are at work here - without trying to explain them and in so doing confusing everyone.
The other is this article which has the sentence „Angefangen hatte alles im Jahr 2005“; where the past participle has been moved to position 1 just for stylistic effect it appears as the sentence works perfectly fine as „Alles hatte im Jahr 2005 angefangen“.
Many thanks for reminding me of the sentence "Dann wird gegessen!" I felt I had encountered something similar on Duolingo, but could not remember what!
I've learned a few things now:
"Es wird getrunken nur ...", as suggested by SIgridKahl1, is correct. However, this should not be literally translated as "It is drunk only ..." since that would assume that whatever "it" refers to was mentioned before the sentence. (In reality, there was no mention of drinking nor what was being drunk before the sentence. See the article itself.)
In the words of canoo.net: "With this type of werden-passive the subject is empty, i.e. the sentence has no grammatical subject. The impersonal pronoun "Es" is introduced as the formal subject of the sentence:"
It therefore makes sense (to me) to omit the empty subject! In the end, for native English speakers, this is indeed a strange form of the passive voice in German, in which neither the agent doing the act nor the object acted upon is mentioned, just the act itself!
See also the link.
Es wird getrunken can mean two things -- the es can be a meaningful subject ("it is (being) drunk") or it can be a dummy subject that is only there to fill the place before the verb, in which case this is an impersonal passive ("drinking happens").
If you put something else before the verb, then in the second case this es simply disappears -- the slot before the verb is filled by that other thing and so the es is no longer needed.
In the first instance, where:
the es can be a meaningful subject ("it is drink")
wouldn't this still be a passive construction meaning something like "it is being drunk"? For example „Mein Bier ist weg! Es wurde getrunken!“ (obviously this is more than just a little bit contrived).
Everything you said about the impersonal passive matches what (little) I know about it.