Quote Originally Posted by RedFox View Post

You should also note, that Russian has the Partitive Case, which is rarely mentioned in textbooks:

бутылка воды́. (Singular, Partitive)
Принесите воды́, пожалуйста. (Singular, Partitive)
Можно мне, пожалуйста, воды́. (Singular, Partitive)

Partitive is used instead of Genitive or Accusative, when we speak about some limited amount of X, not about all the X on the planet. Partitive looks like Genitive for most nouns. For some nouns, Partitive looks like Dative:
налить чаю
стакан сахару
Russian is unique in constantly sneaking in more cases when you think you are starting to grasp the first 6... Where can I learn more about this partitive? What distinguishes it from genitive? Would we always use this case in the examples you used? I thought this whole time these were dative case sentences, then thought maybe accusative, now I see that it's actually partitive.. Hm.