I don't understand this. I do the same Duolingo Esperanto course, and for me, the sentence, "Jen la detruo fare de la musoj" only comes in this lesson. (It may crop up in some of the revision lessons, but as far as I can remember, it hasn't for me). But of course I may have completely misunderstood what you meant!
What is the deal with using adverbs as participles, or as some kind of stand-in for a regular verb? Everything we've read up to this point says -e is for adverbs (describing how an actions was performed), and on the surface this sentence doesn't follow any of the rules that have been presented thus far in the course.
(Disclaimer: I'm just another learner, i could be wrong. If so i welcome corrections!)
I've been puzzling over this for awhile myself, so i did a bit of searching around and found a thread (en Esperanto) on Lernu! on this exact sentence. The general consensus seemed to be that both "fare de" and "farita de" (or even "farata de", if the mice were still working!) are correct. I couldn't find anything on why -e is used, but "fare de" appears to be treated together as a preposition (equivalent to "made by") rather than an adverb followed by "de".
One potential reason to use "fare de" in lieu of a participle is that it does not require knowing the timing of the event. To use "farita" we need to decide between it and "farata" or even "farota". Here past tense is logical, but other sentences might not be so clear cut.
The reasoning for "fare de" revolves around what happens if "fare" was omitted as in "Jen la detruo de la musoj." Here the sentence is ambiguous, and "the destruction of the mice" can be interpreted as the mice BEING destroyed as opposed to being the culprits.
Regarding whether or not "faris" would work, i'm unsure of it but i suspect that since "Jen" functions similarly to a verb (here IS), you may not be able to just insert a non-infinitive verb without changing the sentence further.
Hopefully somebody with a bit more knowledge can shed some light on exactly what is going on here.
I'm having a similar feeling about pere de except that there we are turning a preposition per-which is already adverbial- into a grammatical adverb in a prepositional phrase! And it is seemingly purely to slightly narrow the meaning. This seems highly idiomatic and I don't see that it has any of the justifications you cite here. Do you have any thoughts on this?
I've always been a little iffy on the distinction between "per" and "pere de" but I tend to think of them thus:
- "per" = via, with
- "pere de" = by means of
Step by Step in Esperanto offers this example sentence:
- "Mi povas marŝi per helpo de (pere de) bastono."
Is there much difference?
- Mi povas marŝi per helpo de bastono.
- Mi povas marŝi pere de bastono.
- Mi povas marŝi per bastono.
This is what catches me out in Esperanto. Adverbs seem to be able to modify anything, not just verbs and adjectives as would normally be the case in English. Here the mice and the the destruction are both nouns. On the other hand "of the mice" is really an adjectival phrase so it does make sense. I might get there in the end.
I agree that "jen" can act as a stand-in for a verb.
"Jen" literally translates to "Ecco" in Italian and "Ecce" in Latin, neither of which require a verb when being used in a sentence.
For example, "Ecce homo!" ("Behold the man!") is grammatically correct Latin, despite the lack of a verb.
"Destruction made by the mice" sounds very unnatural in British English. We'd say something such as, "Here is the destruction the mice did" or "Here is the destruction done by the mice". After all, "fari" can mean "to do".
Because the verb "fari" is transitive, that is, it must have an object, as it does in your alternative, "La musoj faris la detruon."
I agree with Markqz about not hearing the 'l' in 'la'. I suspect that the distinction between 'l' and 'n' is is not always as evident as it is for many English speakers. Vincent, presumably a Nederlander, has no problem. I know an Irish person, long domiciled in England and Australia, whose children made fun of her pronouncing, for instance, 'little' as 'nittle'. It doesn't take much experimenting with tongue, teeth and hard palate to see that they are very close. I only recently came to realise that Japanese speaker's difficulty with the 'l' 'r' pair is not only in speech but also in listening. Their version of the sound has the tongue positioned somewhere between the English speaker's 'r' and 'l'. But, the interesting thing is that the have difficulty distinguishing the sounds, let alone reproducing them. (I once spent some time with a Japanese person in Tokyo eating crab in a club. He said he couldn't tell the difference between 'crab' and 'club'. Try it with a Japanese accent!) I read in a book by Gabriel Wyner (Fluent Forever) that a simple computer program can be used to train the ear to distinguish between the sounds. Finally, I sometimes find Duo's narrator seems to put an 'i' before 'j' as in 'Jen'. So I hear the start of this (in crude English phonetics) as 'eeyenna'.