You jest, but in fact nerf is the French singular for nerve.
Not true. I stopped at the store today and bought just a single zucchinum.
Being an Italian word, shouldn’t it be zucchino?
You’re just having the wrong kind of conversations 
As James Fowler observed, “We should keep in mind that most of the Biblical information we have about the charismata comes from the context of corrective enjoinders necessitated by misunderstanding and abuse.”
Courgette
Yes, in Italian the singular is zucchino, but in English zucchini has become accepted as a singular, and zucchinis as plural.
Paparazzi is another word rarely seen in English in the singular. It comes from Paparazzo, a character in Fellini’s La Dolce Vita, so it’s not even a proper Italian word. I’m not sure I’ve ever seen paparazzo in the wild in English. If reference is made to a single one, it’s usually as “a member of the paparazzi.”
You’d think! Yes!
Weirdly, the actual Italian word is zucchina, plural zucchine. It’s the diminutive of zucca ‘gourd’, which is feminine. The masculinized plural in -i is what got borrowed into English. There is no zucchino (at least not in standard Italian; dialect is possibly another matter).
Zucchini is a word without a singular. It isn’t even a plurale tantum, a plural word for a single object, like scissors or trousers. It’s just an anomaly.
Some words for pasta get mangled in the transition to English. For example, *linguina *is the diminutive of lingua, so a bowl of them is linguine. But English speakers usually say “lin-GWEEN-ee” instead of “lin-GWEEN-ay” so it gets misspelled as linguini.
Oooo! That reminds me of one of my favorite cookbooks. Well, it’s theme tickles me even though I haven’t tried many of the recipes yet.
Yes, something like that. Except that the original feminine plural linguine has survived as the spelling in English, while that final vowel change has stuck in the English spelling of zucchini.
Similar thing happened with the Polish word “pierogi,” which is common in certain parts in the US and Canada, though I understand it may not be universally known. In Polish, it is already plural. One pieróg or pierog (there seems to be some debate about this. We used the latter in our family, but the former seems to be the standard version). Many pierogi (when used in the nominative–I won’t get into declensions and all that.) But, in the US, it’s used as “one pierogi, many pierogis.” Which makes sense, as it came into English in the Polish native plural, was re-analyzed to conform to English, and the plural ended up pluralized in English.
A similar thing happens with my father’s (and other native Poles who moved to America and adapted a sort of Polish-English hybrid with some words). My dad, for example, uses “hot dogs” in the singular in Polish. Ten hotdogs mi smakuje (“This hot dog tastes good to me.”) And then, when he needs to make it plural in Polish, he tacks on the appropriate Polish plural marker, “y” in this case, to make it hotdogsy (though pronounced as if it were spelled hadoksy in Polish.) That said, it’s a quirk of Chicago Polish, or possibly even just a family quirk. In Poland, it would be hot dog and hot dogi. (Actually, now googling around, it appears there are “hot dogsy” usages of the plural on Polish websites originating in Poland, though “hot dogi” seems to be the more accepted plural. So it’s not just a family or Chicago quirk (though it is possible it came back into Poland via American Poles.)