Translation:A woman and a man are eating dinner.
The most simple answer is Kolacja is most often subject of the sentence. Dinner is ready, Dinner is at 9. Dinner is warm
kolację is a direct object of many verbs. Jem kolację/I eat dinner. Gotuję kolację I cook dinner. Niosę kolację I am carrying dinner.
It is also after certain prepositions. For dinner/ na kolację
After different verbs, or prepositiona, or "na" in different meaning , or negation dinner can take different forms
Think of it this way, you use accusative case when something is being verb-ed.
Dinner is served.
She is eating dinner.
In the first sentence, dinner is the subject or doing the action (in this case, being served). Therefore nominative case is used. In the second sentence, accusative is used since it's having something done to it. Hope that helps. It's confusing. German is a great way to understand cases. At least a few of them.
Water is never "wode", but it can be "wodę" Polish nouns change depending on their function in the sentence.
Woda is singular nominative- "dictionary form", that is a subject of the sentence, and in some expressions.
Water is tasty. Woda jest smaczna.
Wodę is singular accusative. Accusative is a form of noun that occurs as direct object of many verbs. I have water- Mam wodę. I drink water- Piję wodę.
There are other forms of woda depending on verbs and prepositions they follow, and the function they have in sentence, and other versions for plural
Accusative Endings (for nouns and adjectives) "Biernik" = Accusative
The accusative actually makes four distinctions in terms of gender, instead of the usual three (masculine, feminine and neuter) adopted by polish case rules. Here we have a separate rule for masculine animate (essentially people and animals), masculine inanimate, feminine and neuter. Contrary to what you may be thinking, this distinction can actually make things easier, as there is actually no change for masculine inanimate nouns or neuter nouns in the accusative; their endings always stay the same.
Masculine animate nouns in the accusative add the ending -a, and their corresponding adjectives add the ending -ego.
For example, the sentence "I have a good cat", would read "mam dobry kot", if we wrote it using the nominative case. But, because 'mam' (I have) is a transitive verb, its object, the 'dobry kot' (good cat), needs to be in accusative: Mam dobrego kota.
All feminine nouns in the accusative change their -a ending to -ę, while their corresponding adjectives change their ending to -ą. Let's use a similar example. "I have a pretty daughter" would read "mam piękna córka" if we wrote it in the nominative. But, in the correct accusative case, the sentence is transformed to, 'mam piękną córkę.
As we have already said, there are absolutely no changes needed when using masculine inanimate nouns, or neuter nouns in the accusative case. So, a sentence like "I love my town", reads "Kocham moje miasto" in both the nominative and accusative, because the noun miasto (town) is neuter. Plurals It's best to concentrate on memorizing the singular rules first and then moving onto the plurals, which are, briefly, as follows:
For masculine personal nouns the ending -ów is used (studentów (students)) while all other masculine plurals follow the same rule as the nominative.
For feminine plurals the ending is -y (dziewczyny (girls)), while neuter plurals have the ending -a: drzewo (tree) becomes drzewa (trees).
Polish-Dictionary.com Learn The Polish Accusative Case - [ ] https://polish-dictionary.com/polish-accusative-case
It shouldn't be rejected. Report it. But the articles do matter. "A man and a woman eat dinner," sounds a bit unnatural in this context. It sounds too general, too ambiguous. Which man and which woman eat dinner? Why do they eat dinner? Why wouldn't they eat dinner habitually? Doesn't everyone eat dinner? A better sentence would be "The man and woman eat dinner." This sentence is referring to a definite man and woman, so it makes sense that these two particular people (habitually) eat dinner.
But if you say "A man and woman are eating dinner," then it's a man and woman you're not familiar with, but their current activity at the moment, "eating dinner," is precise and unambiguous.
I agree with you. Yours is not wrong. You should report it. In Polish there are no articles, so it's determined by context. I just think that in English, combining indefinite article "a" with the habitual verb "eat" is the weakest choice of the four possible choices because of logic and the ambiguity I wrote above. All three other possibilities would be better.
The man and the woman eat dinner. Because we know WHICH man and woman.
A man and a woman are eating dinner. We don't know them, but we know what they are doing at the moment.
The man and the woman are eating dinner. These specific man and woman are doing a specific activity at the moment.
A man and a woman eat dinner. Who? When? Why? Why wouldn't they? Doesn't everybody?