In certain contexts this can be as idiomatic as any phrase:
Pete just won the most beautiful horse contest with his pet horse Lightning Angel. One day Pete and Johnny happen to walk past eachother. Johnny looks back and sees Pete. Suddenly he says: "HEY, YOU OVER THERE, YOU'RE PETE, RIGHT?" . Pete isn't that used to his fame yet so he says: "How did you know?". Johnny responds "Easy, you have the beautiful horse. what was her name again?" to which Pete answers: It's Lightning Angel
same observation as before with ”the new oven”, here the translation is more like ”your horse is beautiful” (calul vostru este frumos). To accentuate the definite article, most Romanians will say ”voi aveți calul cel frumos” or ”voi aveți calul ăla frumos”, etc.
Why is it frumos and not frumosul? Where would you use the definite form of an adjective, if not with a definite noun?
I've read that noun+article + adjective is the standard construction but that an alternative can be used when you want to emphasise the adjective: adjective+article + noun.
You're right - I was nowhere near as far along in my studies when I asked this. You only use the definite form of an adjective if it's phrased adjective before the noun.
So frumosul cal and calul frumos both mean beautiful horse.
Regardless of the comment You have a beautiful horse should be correct or the horse is beautiful.thats if English is properly used
I disagree. The given translation is correct for the Romanian, and it's also appropriate in English usage. By allowing "you have A beautiful horse." when that's not grammatically correct, you kind of destroy the point of having definite and indefinite articles. "A beautiful horse" means one random one of many. "THE beautiful horse" means a specific one. They're not the same thing, at all, and English and Romanian both cater to both options.
Articles in English actually have a different shade of meaning when they describe grammatical objects rather than subjects, and it's less about specificity.
For this exercise, when you are talking about a horse that a person owns then by definition it must be specific. The difference between the articles becomes thus:
"You have a beautiful horse" means the horse that you have (or your horse) is beautiful.
"You have the beautiful horse" requires that the horse in question has been previously mentioned as being beautiful and this sentence is clarifying that the horse you own and the beautiful one mentioned are one and the same.
As with most sentence/phrase examples in Duolingo, this is ambiguous without further context; as a result, what you said doesn't fundamentally disagree with what I said - "You have a beautiful horse." still means one of potentially many because they might also have several ugly horses, or even though their horse is beautiful there are still other beautiful horses around or potentially being discussed/referenced, whereas using THE is very specific. So while I don't fundamentally disagree that it's more nuanced than my initial comment, the use of "The" rather than "A" means that it does still, even using your distinction, include an increased level of specificity, but I guess your interpretation may vary.
However, the initial point was simply to give an example where the sentence, as given, was translated correctly and accurate in English usage rather than covering all the bases. :)