"There are some apples here."
Translation:Van itt néhány alma.
Néhány alma is the subject of the sentence (which could also be translated as, "Some apples are here," to make that a little more clear). It is not the object of any action that would require the accusative ending. Compare...
Van itt néhány alma (there are some apples here or "some apples are here"; nominative)
Tedd le az almát (put down the apple; accusative, the apple is the thing that is to be put down)
Az alma János előtt van. (The apple is in front of János: apple is the subject)
János megeszi az almát. (János eats the apple: apple is the object which is being eaten)
Hol van az alma? (Where is the apple? Subject)
Elfelejtettem az almát (I forgot the apple. Object.)
Hungarian uses the singular form of nouns if they are modified by a number or most other quantity words, including néhány (some) and sok (many). The verb will match the singular form of the noun. So for example
Van itt néhány alma. (There are some apples here - but alma is singular, and we use van with it)
Van itt hat alma. (There are six apples here - but alma is still singular, and we use van)
Van itt sok alma. (There are a lot of apples here.)
Vannak itt almák. (There are apples here - plural apples, plural verb.)
Hungarian doesn't duplicate words to express plurals. The volume expression, in this case "néhány" already expresses that one is talking about more than one item, so no need to indicate that fact again with the noun (alma/almák, the latter in this case would be incorrect.)
You're welcome. Not trying to confuse you but there's a bit more to the rule above, e.g. "azok az almák", or "vannak almák" (those apples/there are apples) would be correct but that's because said sentences don't contain counter words, so while "azok" is a plural (of 'az') and "vannak" is a plural (of 'van'), in those cases one would introduce the noun as plurals as well. Hope that makes sense (?)