"He has many friends, I do not have any."
Translation:Lui ha molti amici, io non ne ho alcuno.
It's not a negative, it's a partitive. It replaces the imaginary prepositional phrase "of them". In Italian, when things are part of an implied set, you need to refer specifically to that set rather than just imagining it.
So to compare this to another sentence you've probably seen, to express "He received seven in total", you have to say literally "He received seven OF THEM in total". So NOT "Ha ricevute sette in totale", but "Ne ha ricevute sette in totale."
The 'ne' in this sentence plays the same role. So literally it means: "He has many friends, I don't have any OF THEM." In English the set of "friends" is implied, but in Italian you have to state it explicitly.
It might be easier to understand here if you translate "alcuno" as "at least one." Making it "he has many friends, and I don't have at least one." or "...and I don't even have one." "Friends" here is plural, but "one" is singular.
This is exactly what the Italian is doing "Amici" is plural, but "alcuno" is singular.
Maybe. I grew up in an immigrant family with grandparents who didn't speak English but I never took any classes in Italian (and my family spoke dialect) so my grammar is not so good. I'm pretty sure 'tanti amici' is grammatically correct and I also suspect you can translate it as 'many friends'. Hopefully a native speaker of Italian will weigh in.
I might be wrong, this is just what I've observed so, take it for what it's worth.
"Alcuno" means "some." "Qualsiasi" means "any." In English we kind of slide between these two words sometimes and use "any" where we mean "some." This is usually in the negative: "not some" doesn't sound right to us, instead we'd say "not any." But Italians don't do that, they would say "not some" (ne aluco).
This might also help. "Qualsiasi" looks similar to "quali" because the two are related.
"Quale vuoi?" (Which do you want?) "Qualsiasi" (Any, or whichever)
No, the correct one is : "lui ha molti amici io non ne ho nessuno" http://www.accademiadellacrusca.it/en/italian-language/language-consulting/questions-answers/costruzione-frase-negativa-italiano
I think it should be acceptable, except that the plural of 'amica is 'amiche', not 'amice'. This is apparently to keep the hard 'c' as you go from singular to plural, amica->amiche, though why you should have to keep it for the feminine case and not for the masculine one (amico->amici) is not explained. It is how it is.
See mdsawyermd's post very close to the top of the current thread. Or f.formica's post at the top of this one: https://forum.duolingo.com/comment/618448/What-is-the-difference-between-alcuno-alcuna-and-alcuni
Interesting question. I think that 'ne' relates to the noun "amici" rather than the particular persons whom "lui" has as friends. So 'ne' is saying "of them", but the "them" is friends in general, not the specific friends of "lui" previously mentioned.
There's probably a better way of putting this, but I hope you see what I mean.
Ah I see. Yes that's right. Except that if you wanted to repeat the noun (and not use "ne") you would need to use the singular "alcun amico": io non ho alcun amico.
(Note that here "alcun" is an adjective, while in the original example at the head of the the thread "alcuno" is a pronoun: that accounts for the different endings even though both are singular!)
For more on this, see mdsawyermd's post very close to the top of the current thread. Or f.formica's post at the top of this one: https://forum.duolingo.com/comment/618448/What-is-the-difference-between-alcuno-alcuna-and-alcuni