From what I have been able to find out, the only valid translation for "Το ποτήρι του χυμού" should be "the juice glass" (i.e. the glass used to serve juice in). In contrast, "the glass of juice" should be "Το ποτήρι χυμός," right?
I would never use a sentence like "το ποτήρι του χυμού" to talk about a glass of juice. You're right about "the juice glass"... Commonly, you would hear "ένα ποτήρι χυμό" (a glass of juice), "το ποτήρι με τον χυμό" (the glass of juice), "αυτό το ποτήρι με χυμό" (this glass of juice), "πόσα ποτήρια χυμό;" (how many glasses of juice?) . I'm sorry if it seems too confusing, but that's the way graecophone people commonly speak!
Ευχαριστώ for the accessible explanation! Έχω μια ερώτηση παρακαλώ: why το ποτήρι χυμό and not ...χυμός? Is there a reason for the accusative case, or is it just an arbitrary grammatical expression?
This seems to be another multi-service sentence. "Το ποτήρι του χυμού" is both the glass used for juice but also "the glass of juice". This is making me think of rather comical exchanges in Greek over which it should be. But as with all languages, it works out in the end. Thanks again.
It's exclusively the glass used for juice! A glass of juice would be either "ένα ποτήρι χυμό" or "το ποτήρι με τον χυμό".
"A glass of juice." would be "Ένα ποτήρι χυμού," where instead of the definite article the we use the indefinite article a. "the glass with the juice" is not a translation suggested by Duolingo it is a description of the Greek but not one we would use in English.