"The ghosts always come at midnight."
Translation:Um Mitternacht kommen immer die Geister.
No, it is Geister See https://www.korrekturen.de/flexion/deklination/Geist/
Something just occurred to me that I didn’t think of when previously encountering this sentence. There’s an ambiguity in the English sentence. It could either mean “On the occasions when the ghosts come, they only do so at midnight”, or it could mean “Every time midnight comes around, the ghosts come.” Does the German sentence also have both meanings, or would, say, a change in word order differentiate the two?
It might help to remember that "am" is a contraction of "an dem", and since "dem" is dative masculine and neuter, it can only precede nouns of those genders. Mitternacht on the other hand is feminine, so you know you can't use "am". (I know it's still a bit confusing as to why you use an Vs um but it might help a little!)
In my mind, Mitternacht is an exact point in time, so you use the same preposition as with times of the day: um 0 Uhr, um Mitternacht. But Mittag is a period rather than a point (I would say roughly from 11am to about 1 or 2pm), so it uses the same preposition as other such periods: am Morgen, am Vormittag, am Mittag, am Nachmittag, am Abend.
Even though I said "midday" for the sake of alliteration in my original post, I've been thinking of "Mittag" as meaning "noon", i.e. 12:00 p.m., so it seemed odd for it to use a different preposition than another word that I also took to be a specific time. Especially when those two words are so closely related (word for "middle" + word for one of the two halves of the day).
Why is the verb neither in the second position nor at the end?
In the presented solution:
Um Mitternacht kommen immer die Geister.
The verb is in the second position.
"Um Mitternacht immer die Geister kommen" is wrong?
This is a main clause, so the verb has to be in the second position (as shown above). If this were a subordinate clause, your word order would be correct.
“Second position” doesn’t mean it’s the second word in the sentence, just the second thing. So, it’s not that um doesn’t count, it’s that um Mitternacht, as a whole phrase, is the first position. Just like, if you put the subject first, you would say “die Geister kommen”, and die Geister is all in the first position, even though it’s two words.
Word order is confusing and look like poetic . I feel it as a language of Shakespeare. I miss the order of words very often due to my familiarity with English. Um Mitternacht kommen immer die Geister =At midnight come the Ghosts. This sentence is a generalised sentence relating to belief of ghosts.The sentence also should have been in general form but why it is in the poetic order.
An argument can certainly be made, however, good practice when translating on Duolingo is to translate as closely/literally/directly as possible with correct grammar.
There are exceptions (both where the translation isn't necessarily as close as possible, and where correct grammar isn't upheld), but that's the rule of thumb.
Ironically, if you worked as a professional translator, yours might be preferable. The task wouldn't be to answer the question, but to express a sentiment, and yours does a better job, even though it might not make sense for Duolingo to accept it. The goal here isn't to come up with what's the best answer conceptually, but one that expresses the specifics of the original sentence to the extent possible.