pocolo why not poculum?
Ablative - see https://en.wiktionary.org/wiki/poculum#Declension
(most words do not have a proper locative case)
Why does the "est" go in the middle and not in the end of the sentence?
Both positions are OK.
Even at the beginning is OK.
is this another example of a correct answer that wasn't coded as correct? (in poculo vinum rubrum est)
Is it redundant to ask whether vinum being neutral, being 2nd declension, or being both, determines how its nominative singular, likewise takes rubrum (adjective) in agreement, rather than ruber (masc) or rubri(fem)?