Translation:Which piece of furniture is the frog sitting down on, the armchair or the shelf?
The problem is, English scentences such as this may be an adequate representation of the Hungarian text that help us to understand Hungarian grammar and sentence structure, but it is well nigh impossible to guess the correct answer. So we have to memorize bad English in order to answer correctly.
In my experience, this is the case for just about every language. There are certain things that just don't sound right when translated literally. It's not that bad in, say, French-to-English or Spanish-to-English because there are a lot more sentences that DO translate literally and there are regular rules for sentences that don't (e.g. "qu'est-ce que" always means "what", "il y a" always means "there is", etc.) For those types of sentences duolingo usually accepts both the literal translation and the best English one, and it's not too taxing on the developers. The problem I'm seeing with Hungarian is that there are FAR MORE sentences that make improper English when translated literally, and the developers seem to be straining to incorporate all possible correct translations. The flaw, I think, is in the design of the duolingo courses themselves. The most effective way to learn Hungarian would probably be to learn the "bad English" literal translation to understand how Hungarian uses its prepositions, as well as the correct English translation to understand what the sentence is actually saying for every sentence. One translation per one sentence can't accomplish this, and with the course being incomplete at this time it really just leads to confusion.
Maybe frogs can sit on armchairs although I wouldn't say that's the issue. Just as English permits flexibility about whether we sit in or on any kind of chair, so does Hungarian. Here, we're being told that it's on the armchair although there will be many instances where it's in and we'll see be rather than re.
The translation in the model answer isn't how we speak in English. We don't need piece of furniture and we don't need down. Which furniture does the frog sit on, the armchair or the shelf? That's enough and it isn't necessarily static as suggested. The act of sitting is conveyed. If we use present continuous, which furniture is the frog sitting on etc, then it's static.
From a Hungarian view, 'sit on' can mean two things. It can be a long-term static condition (German: wo, Russian: где), or a target of a movement (German: wohin, Russian: куда). Unfortunately, English language lacks a word like "to-where". If I want to be sure to express the second one, I have to use "onto", because it is exactly what I wish to say.