Ah, like es gibt... This makes more sense if I use a more familiar sentence as a reference point:
Er trinkt / Es gibt
He drinks / It exists
Er hat nie getrunken / Es hat nie gegeben
He has never drunk / It has never existed
So this seems clear so far. Then we introduce the accusative part of the sentence:
Er trinkt Wein / Es gibt Wein
He drinks wine / Wine exists
Er hat Wein nie getrunken / Es hat Wein nie gegeben
He has never drunk wine / Wine has never existed
Breaking it down into those steps seems to allow my brain to keep up. Please let me know if it needs any corrections (for example I'm not sure if Es gibt is a complete sentence, but I think it illustrates the point).
I was having trouble with identifying the subject here. Could it be "Es" or "diese Person"? I think I cracked it but tell me if I'm wrong.
In English the subject is "This person", but in German because of "Es... gegeben", like "es gibt", the subject has swapped. The literal translation would be "It has never been this person", with "It" as the subject. Meaning "diese Person" is the object in the accusative form.
Am I right?
Certain phrases in German like this confuse me, like how "Es gefällt mir" becomes "I like it" and the subject/object has swapped. But I'll get used to it.
Just to clarify, "diese Person" is in fact accusative. "Es gibt/Es gab/Es hat ... gegeben" always the accusative case. If you replace "diese Person" with a masculine noun, you'll get "Es hat diesen Mann nie gegeben". In terms of thematic roles, of course, "diese Person" is the agent and "es" is just a dummy pronoun.
DTipps, here's my two bits on your problem with es gefällt mir. In English this would be a passive sentence, it is liked by me, i think some verbs in German are always used in passive voice, gefallen being one of them, however this is an assumption for my comprehension of the language. Ich mag dich( i like you), du gefällst mir(you are liked by me). I guess for some reason the verb itself changes in the passive voice in German.
Google translate says no, FWIW - https://translate.google.com/?source=osdd#en/de/This%20person%20has%20never%20existed
How can you talk about "this person" if he never existed? I answered "there has never been such a person" Marked wrong but I still think it is the answer that makes the most sense. Could this sentence also not be: "this person has never been there" - ( so he couldn't have committed the crime) ?
I agree with SydneyBlak4. If we talk about a person of uncertain historicity, eg Merlin the Wizard, we could say 'this person never existed', but if we talk about someone of no historicity whatsoever, eg the "president" of the UK, we would say 'such a person never existed'.
"This person has never existed" is not correct English. Given that they do not exist, you cannot point out this person. "That person has never existed" should be the only acceptable version. It is a very tortured example to try and come up with a formulation where "this" works. If we are talking about say a perfect role model, or Merlin, we would say "such a person has never existed". We might say, "That person never existed." About the only formulation I think might work would be considering whether you have a photofit of a suspect where you discover it was based on lies.
In other words, another poor sentence where we spend more time trying to make sense of Duo than making sense of German.
Ok. It took me three tries to wrangle this sentence initially, but now that I have read your explanation and re-read it a few times back & forth, it makes more sense. "Diese Person hat nie existiert." still seems more straightforward. Nevertheless, thank you for your explanation, Christian, helps a lot!