If you try to "make sense" of the language, you're never going to learn it. Think of how much in English doesn't make sense when you look at it literally.
when someone "runs away from home", it doesn't necessarily mean someone is literally running, for example. And someone who is literally running away from their home may not be running away from home.
You can "look up to someone" without looking up, or even looking.
Accept that a word means what it does, and things will be much simpler.
In this case, one of (MANY) meanings of "en" is "made of" (http://www.wordreference.com/fren/en)
O.k. Lets see if this makes sense.
En (and Y) are often used to represent something that is absent from the sentence. There are rules that sometimes favor one or another. There are rules and conventions that limit what they can represent. Oten the sentence itself provides sufficient context within those rules to indicate what they stand for. Other sentences require previous context to make it possible to properly translate them. Occasionally the reader/listener has to supply the context.
You are right that you shouldn't look for "what makes sense" in a new language, because it means what you feel sounds right. English makes perfect sense, as does french...!
though i have to point out that you are failing with your reasoning all your examples are figures of speech! which is a totally different story than what we are dealing with here
I disagree that by trying to "make sense" of a language, you are never going to learn it. I find that some of my best revelations and a-ha moments in language learning come from constantly asking "why". Attempting to make deeper connections has always been more helpful to me than mindless memorization.
Yes, whenever a new concept is introduced I basically memorize the pattern until I can either figure out the underlying rule or I read the rule in the comments. Duolingo could be vastly improved by including some simple explanations of the underlying rules when introducing new concepts.
This is true, but it's always helpful to dig into grammar for the "why". Duo gives two correct answers for this: "It is in what?" and "What is it made of?" which seem to be wildly different, like asking "flour is in what foods"" AND "flour is made of what?" all from the tiny french word "en". Are we talking about the part or the whole? It's confusing. Writing it off to "just memorize it because it's a different language" doesn't always help.
But, now that we know that en has many meanings and one of them is "made of" DOES help.
The meaning “made of” in this sentence is in the French word ‘en’. Imagine you see a ring you like in a jewelry shop, but it's made of silver and you would prefer gold. In English, you would probably just ask “Do you have this in gold?”, rather than “Do you have this made of gold?”. But if you want to know what it's made of, you can't just ask “What is this in?”. English is a weird language.
While most people would certainly say, "What is it made of," it is silly that "Of what is it made?" is actually marked incorrect. If you are interested in writing formal academic papers, you will need to avoid ending sentences with prepositions. The rule isn't observed by most, but it still does live.
Curiously, this custom entered our language sometime during the Pan-Hellenistic movement, when the British tried to connect their Roman roots and to incorporate Latinate customs into English. In older versions of English, this current rule is violated even by scholars, because it was not observed. Ditto with splitting infinitives.
The main problem here is that we have no context! so how are we supposed to guess what it is supposed to mean?
Also translated it would be "It is in what?" I am pretty sure this is not used, or not used anymore! "c'est fait en quoi ?" if this was the phrase we probably wouldnt be having this discussion! who at duolingo comes up with these strange sentences? o.O get some french people to help you!
You need to stop thinking of English and French (or any other language) as literal, complete equivalents.
To learn another language, you have to realize it exists 100% independently of English (grammar/syntax wise; vocabulary is excepted). Get out of the English mindset and try to take French for what it is.
One way I can think to help you think of it is if you say, "The story is written in French." What language IS IT IN? It is in French. So just like you would use "it is in" to talk about language, you could talk about materials, like a coat made of leather. For example, in French you could ask, "What material is it in?"
It works as a preposition too.
In another forum on this phrase, Sitesurf (who we all revere :) commented: "Ugly French. More correct versions (from very formal to relaxed): en quoi est-ce (fait) ? en quoi est-ce que c'est (fait) ?"
There followed an interesting discussion between Sitesurf and jrikhal (another fine native contributer) over the acceptability of the more colloquial version and what the Académie had to say about it all. Check here for the discussion between our top French mentors: https://www.duolingo.com/comment/1085095