Translation:Some students are eating apples and the others do not eat apples.
I'm confused as to why in the first clause it is "des pommes" and in the second it is "de pommes"?
Because of the negative form "ne ...pas de ..." or "ne ... pas d'..." (when the noun after starts with a vowel).
While I'm asking questions... In English, we would rarely state the entire verb phrase twice - "Some students [do something] and others don't" would be usual.
Is there a usual way of expressing this in French, or would we just expect to repeat the whole thing?
I wrote pupils because that's what I remember learning it forty years ago lol
"pupil" is correct as well, and should be accepted if it's not already the case.
Yeah, it's strange. Not wrong, but strange. "A few...but most" would be better (in English), or perhaps "These...but those are," but that would probably require refining the french phrase.
I had been taught that if you were indicating only some of a group to make a comparison, you would use "certains" - "certains élèves mangent..." So is "des élèves" just less formal than this, or is there some shade of meaning I'm missing?
Well, I would personally use "certains", but I can't say that using "des" is incorrect, even though it's only some students among others.
I had assumed that some students were eating apples, and other non-students were not eating apples.
If you break the sentence apart: 1) Des élèves mangent des pommes = (Some) students eat (are eating) apples (not "the apples") Ref the partitive "des" for plural countable things: http://french.about.com/od/grammar/a/de-vs-du-de-la-des_2.htm
The second phrase has to do with "the others" who "ne mangent pas de pommes" does not use the partitive, so they "do not eat apples" and not that they "are not eating (some) apples."
What is the age range of an élève? For some reason I'm thinking of a little student (or pupil). Maybe it's because it sounds a bit like elf
"élève" goes from "école primaire" (primary school) to "lycée" (high school), so basically from 6 to 18. After that we rather use "étudiant". But the difference is not that clear, because "élève" can simply designate someone learning from someone else, no matter the context, so even adults can be called "élèves", it's not a problem.
Both "pupil" and "student" can mean "élève", but only "student" can mean "étudiant".
Those others who do not eat apples can be also students? Or they must be /can't be students? Or we don't know from this sentence?
Is this meant to be a general statement? I am particularly referring to "les autres" here.
I mean, "Some students [whatever] and others don't" would be a common way, in English, of expressing a general statement.
To say, "Some students do and the others don't" indicates we are talking about a particular group of students, not just students in general.
So - is "les autres" just how it's done in French, or would one say, perhaps, "des autres" for the more general remark?
Why is my answer...some students eat apples and the others are not eating apples...incorrect?
Why is "... the others are not eating apples." considered incorrect? Duolingo said the correct answer is "... the others do not eat apples."