From Tips and Notes:
The Accusative case (Acc.) is usually the case of a noun functioning as the direct object in a sentence.
In other words:
Nouns in the Accusative follow verbs that require some object to act on. So if a noun is in the Accusative, it usually means that something is being done to it.
Verbs that are usually used together with the Accusative case include, among others, very basic words such as mieć (to have) and lubić (to like).
In this particular skill, the key verbs are jeść (to eat) and pić (to drink) – both of them are mostly used with nouns in the Accusative case.
Learn more here.
I try to be respectful when I feel people are confident with what they say. There are many people who learn Polish from their parents, or significant others, and it feels more respectful to say - that is not "standard Polish", then you are wrong.
And I know some people in south-east Poland talk this way. Around the time I wrote that comment I had spent 3 hour train trip with two women who talked like that.
the course does not teach regionalisms, but if someone uses one, and asks about it why not tell about them.
"We've got (a thing)" means the same as "We have (a thing)" in English (at least, in my dialect). "We got" is different, meaning "We previously acquired."
In the former case, you may have always had the thing (despite what the tense makes it seem like), as in "I've got blue eyes." In the latter case, one may not even still have the thing, as in "I got a sandwich, but then I ate it."
There are different patterns, or "declensions" of Polish nouns, depending on gender (actually, there are three masculine declensions, for persons, other animate things, and inanimate things).
So the -a/-ę pattern is because "woda" is feminine, while "chleb" is maculine-inanimate (which has the same form in the nominative and accusative).