I've been studying Esperanto for about two years now, and am now conversing in the international language and reading Esperanto literature at a meznivelo (intermediate level). I had never encountered this particular word ending before someone, perhaps you, made a comment — "mi estas knabiĉo" — in the User-Suggested Translations section of the Duolingo Course Editor. I had to look up the -iĉo ending, and I see that it is a hypothetical "improvement" to the language in the interest of greater gender equality. I'm not in principle opposed to such usage, but as you point out, it is both unusual and unofficial.
You suggest that it could be accepted as an alternative correct answer to particular sentence translations, and again I have no formal objection to this. However, Duolingo software is designed to accommodate the needs of a great many different languages, and is only to a small degree customizable for each of these. The small group of Esperanto course contributors is already struggling mightily with limitations on the total number of characters allowed in all the possible correct answers as we attempt to anticipate possible variant word orders and alternative translations like “beautiful, pretty, handsome,” etc. for bela and so forth, as well as attempt to ensure that the ikso-system is accepted in addition to the supersignitaj aŭ ĉapelitaj literoj (circumflexed letters). We're also trying to compose Tips and Notes sections to explain points opf grammar and usage, as well as writing individual rationales as to why particular suggested translations could not be accpeted, or rewriting the matrices of correct answers when we agree with a particular user's suggested translation.
The fact that Duolingo finally allowed the Esperanto course to graduate from beta testing is a reflection of our successful efforts over a period of many months to reduce the number of outstanding user reports that had not been dealt with previously. Frankly, trying to anticipate when an informal but non-standard usage not approved by the Akademio de Esperanto should be accepted would add a new layer of complexity to an already difficult set of tasks which is carried out entirely by volunteers dedicated to extending and completing the best possible (and as error-free as possible) course.
We're all just doing the best we can. Each of the ten volunteer contributors and administrators is putting in between ten and 20 unpaid hours a week on the Esperanto course outside of our regular employment, and if we were to start adding all the variant possible sentences that incorporated non-standard usage, I think our job would become unmanageable.
I thank you for your valuable suggestion, but I don't see it as something that we could feasibly accomplish at this stage. Perhaps in the future, we could devise a bonus lesson incorporating some of the "reform" suggestions that have achieved at least some informal international acceptance, but right now, we're still trying to reasonably finish the course within our group's capabilities.
Just a hint: El and Ella are pronouns (they replace the subject. It=apple; You=how you're talking to). Articles are words that define the noun. Two types: indefinite (a/an because the noun is general) and definite (the; a specific noun.). Since there aren't genders in Esperanto, you only have La for indefinite. You don't have definite.
I'm one of the contributors to the English to Esperanto course. Listening to the audio, when available, is indeed a good idea, as it will help develop a nice international pronunciation, which will make it easier to make yourself understood at international Esperanto congresses, etc.
The main reason that some audios have been disabled after having been initially posted is that some users have complained about indistinct consonants at the beginnings of the recorded sentences; i.e., they have difficulty distinguishing initial "ni", "mi", "ŝi", "li", etc., or the consonant is entirely clipped off. We're sorry for these little glitches.
Probably when we get around to preparing a round of new audio recordings, we should make sure to start and end each of the individual utterances with a tenth of a second of no sound to prevent this sort of problem from arising anew.
Best success to all the wonderful people learning Esperanto through Duolingo.
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