In Portuguese, "um copo de suco" will mostly be understood as "a glass with juice".
But it can also, but less commonly, be understood as "a glass intended for juice" (much more common for wines and sophiosticated drinks, although there could be other better words like "taça" for wines - taça is that kind of glass with a stem).
But using "um copo para suco" avoids that possible ambiguity. It's indeed "a glass intended for juice".
Um copo de vidro is indeed a glass made of glass.
Thank you. Now I wish I knew why I would ever have asked that question lol. It is almost exactly like the Spanish and it is not something that should have confused me at all. But thank you for your answer to my.last question. I doubt anyone could answer this one.
EDIT Luckily I just came across a Spanish discussion I was watching which referred to another discussion which had referred to yet another discussion which had suggested that in some circumstances you would use con instead of de because de because de might mean that the glass was made of that substance. That must have been where I got confused. But I cannot think of many circumstances where you would confuse the substance in the glass with the substance it was made of. I do remember that both con and de are occasionally used in Spanish though now that I read that comment.
Ah, good to know. At least we can use nouns as adjectives ("A wine glass" vs "A glass of wine") which helps. For some reason a glass intended for lemonade (or at least the tasty Brazilian version) is called a "copo limonada" rather than a "copo de limonada" so why not a "copo suco" and "copo água" etc?
Well, this link has some kind of a snare, because the expression used was "Copo Limonada". The "l" is capitalized, which means Limonada is the name of this specific glass, its "brand" in other words.
If "Limonada" was intended to be used as an adjective for example, than it would surely come without capitalization and with "de",
Copo de limonada. If you see anything different from any of these two possibilites the writer problably doesn't know what is doing.
Yes, thank you, that explains it! The manufacturers seem to have a minimalist approach to naming their products: http://www.cristalblumenau.com.br/200.html
(Actually, the other site talks about "Copo para Suco" and "Copo de Água" and so on, therefore the capitalization didn't strike me as strange.)
Both "sumo" and "ananás" are typically European Portuguese words. Duolingo teaches Brazilian Portuguese and different words are used in Brazil: