How to translate "Centuries before World War I, soldiers often used swords and scabbards." grammatically correctly?

Question

Duolingo translates

Centuries ago, soldiers often used swords and scabbards.

as

Antaŭ jarcentoj, soldatoj ofte uzis glavojn kaj glavingojn.

Inspired by the question, whether "Jarcentoj antaŭ, ..." would absolutely unacceptable, I tried to come up with a sentence that would begin with these words, but where "antaŭ" wouldn't be modifying "jarcentoj" but whatever came after it, so that it'd remain a preposition and the sentence would still be grammatically correct.)

I thought I could do so by expressing

Centuries before World War I, soldiers often used swords and scabbards.

as

Jarcentoj antaŭ la unua mondmilito(,) soldatoj ofte uzis glavojn kaj glavingojn.

But after coming across

Ĉiu diskutota demando estas ja publikigita tri monatojn antaŭ la kongreso.

and

Kvaronon da horo post tiuj vortoj [...] droŝko [...] haltis antaŭ unu el la plej luksaj magazenoj de la strato Senatorska.

and trying to understand why they have an accusative marker (see Why accusative in duration before "antaŭ"?), I concluded that my new sentence was a similar case and would need one (or a rolvorteton), too. (And I couldn't think of a suitable rolvorteton for this case.)

However, if I just apply the "-n", I get

Jarcentojn antaŭ la unua mondmilito(,) soldatoj ofte uzis glavojn kaj glavingojn.

and thus a sentence with two separate phrase parts ("Jarcentojn" and "glavojn kaj glavingojn") in accusative, which AFAIK (and, I think, according to the Konsoltejo's response to this "Duobla akuzativo" question) isn't allowed, even if only the latter is a direct object and the former a point-in-time complement.

I could make the sentence grammatical by not adding the "-n" and prepending the rolvorteto "Dum", but that would give it a duration meaning ("during centuries before WW I") instead of the intended point-in-time meaning ("at some point in time that occurred centuries before WW I").

So how would I correctly translate

Centuries before World War I, soldiers often used swords and scabbards.

?

Answer 1

Many accusatives are allowed. There is only one direct object, but other parts can have accusative too.

(Disregarding directive accusative (la birdo flugas en la ĝardenon = into i.o. in).)

An accusative happens for any non-nominative (non-subject) if it is not preceded by a preposition.

Dum jarcentoj la homoj faris nenion.

Jarcentojn la homoj faris nenion.

Sabaton ni manĝos torton.

Je sabato ni manĝos torton.

Jarcentojn antaŭe, soldatoj ofte uzis glavojn kaj glavingojn.

Antaŭ jarcentoj - antaŭ la unua mondmilito - ...

Answer 2

Most descriptors (in lack of a better word), whether these are prepositions or something else, are in Esperanto put in the front of the main word. Antaŭ is a preposition, so it comes before the main word, which in this case is la unua mondmilito, i.e. antaŭ la unua mondmilito fixes the time reference. If you want to express the idea, that during the centuries before that soldiers often used swords and scabbars, then you can say

Dum jarcentoj antaŭ la unua mondmilito soldatoj ofte uzis glavojn kaj glavingojn.

I wouldn't consider centuries to be a point in time, so that you could say Jarcentojn… or En jarcentoj….

PS. I prefer porti (cf. trägen in German) here, since scabbars aren't used per se but for protecting the bearer and the sword.

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The verbot against the double accusative concerns the case of chained direct objects.

*Mi manĝigis la hundon la viandon.*

Here the dog is the direct object of me making it to eat, and the meat is the direct object of eating itself ("I fed the dog the meat", if that is correct English either). The root cause of this kind of chaining is, that the accusative in Esperanto is kinda overloaded, it is used for too many things. With igi-verbs the accusative is commonly used to denote the receiver of the action (Mi manĝigis la hundon), even though the correct grammatical case would be dative, an indicator for the recipient or beneficiary of an action. Since Esperanto lacks real dative case, one uses the preposition al for that purpose, i.e.

Mi manĝigis al la hundo la viandon.