Here is a site where you can hear pronounced 'nono' and 'nonno' which are the masculine versions of, respectively, 'nona' and 'nonna': http://www.vocabolaudio.com/it and here is a site where you can read about this phenomenon: http://italian.about.com/library/weekly/aa082703a.htm
Shortly, a doubled consonant is pronounced twice and that shortens the preceding vowel. For example, /fato/ [ˈfaː.to] ~ /fatto/ [ˈfat.to] (first one means "fate, destiny" and the second means "fact").
Well, I disagree. As native Spanish speakers, we understand very easily the double consonants in Italian. Since this is something that comes from Latin (the language that gave birth to both Spanish and Italian). I can hear nona insted of nonna. The word "nonna" when pronounced, is separated into two syllables "non-na" making the bowel "o" a bit longer, which is not the case here.
It could work in English, But only in the few cases where the simple present is used, For example the Habitual ("I come in ninth every time"), Or when telling a story. ("So I enter the race, And I come in ninth, And I think "That's pretty good, But I can do better", So I get more practice, And I enter again, And this time I come in fifth!")
It is gramatically correct. I think the point others are making is it appears most uncommon. A will or did or coming or came is more common. The arguement people are trying to communicate is when learning a language please use common terminology. It's difficult enough thinking in terms of common terms.
"I arrive in the ninth" means something different, and would be "Arrivo nella nona" in Italian (though it wouldn't make much sense unless the implied object were known). In English, at least American English, it would mean that you got to the baseball game in the ninth inning. Kind of a specialized usage, certainly not what the original Italian is likely to mean.
BTW, congrats on your streak. 418 -- wow. You must have a boatload of lingots.
In the actual exercise DL said the correct translation is "I'm arriving in ninth"; that is NOT a normal English translation. Here in the discussion thread they say it's "I come in ninth"; that I could sort of understand (although "I came in ninth" would be more typical, indicating order of finish), but NOWHERE did the dictionary hints suggest that "arrive" could be translated as "come in".
Those who finish a race "come in" at whatever position they finish: The first to arrive at the finish line "comes in" first, the second "comes in" second, etc.
In Italian, race participants don't "come in", they "arrive". So to translate the English sentence "I come in ninth", you would say Arrivo nono.
Let's get the idiomatic English correct please. I understand that this is heavily slanted towards American "English", but in Great Britain one does not say " I come ninth", the grammatically correct way to say this is "I CAME ninth". Stop marking this translation as incorrect as it is not.
This has nothing to do with American vs. British dialects. The sentence is rather artificial, in Italian as well as English. Consider a runner about to cross the finish line who is talking on her iPhone with her husband. He asks how she's going to finish, and she says, "Right now, I'm coming in ninth." Perfectly valid English, idiomatic or otherwise. Just a rather unusual and specialized thing to say.
Wen recounting an event it is very common to use the present tense to make the action more immediate. https://dictionary.cambridge.org/grammar/british-grammar/present-verb-forms-referring-to-the-past