Question: just as there is a possessive for the other pronouns (Mi/Mia, Vi/Via, etc.), is there one for "Oni"? And, if not, is "Onia" grammatically correct?

Shmanks!

'Oni' is absolutely correct

Yes onia is correct, although it is pretty rare.

PMEG has the example Ili kapablas ŝteli eĉ oniajn vestaĵojn.

"onia" is definitely correct. But it's not too common so you won't see it frequently.

erinja:"onia" is definitely correct. But it's not too common so you won't see it frequently.

Thanks for the clarification, everyone.
Regarding the reason behind the infrequency of "onia", is it because its tone is excessively formal, something much like the English "one's" (as in "one's ideas are seldom respected")?

Diablo:Thanks for the clarification, everyone.
Regarding the reason behind the infrequency of "onia", is it because its tone is excessively formal, something much like the English "one's" (as in "one's ideas are seldom respected")?

I don't know if I'd call it formality, because "oni" is very common in Esperanto, much more common than "one" in English.

I think part of the reason is that Esperanto has other words that can (or must) be used in situations where we'd use "one's" in English, so those other words end up being used instead of "onia'. For example, if "onia" is the object of a sentence, referring back to the subject "oni", we have the word "si", to use, the reflexive pronoun.

The word "ies" (someone's) is another good way to talk about impersonal possession.

For example, it sounds very formal in English to say "One must always bring one's wallet". In Esperanto, that ends up as "Oni ĉiam devas kunporti sian monujon".

You can see how that doesn't use "onia".

Another reason is that if you are over-using "onia", the question becomes, "Why are you being so vague about who you're talking about?". It starts to sound evasive.

And yet another reason is that sometimes it can simply be left out. Sometimes instead of saying, for example, "oniaj ideoj", you can just say "la ideoj", because it's understood through context that ideas belong to someone, they don't pop out of thin air. "onia volo" - that can often simply be "la volo", because someone has to want something, have the will for something, it also doesn't occur in a vacuum.

erinja:

Diablo:Thanks for the clarification, everyone.
Regarding the reason behind the infrequency of "onia", is it because its tone is excessively formal, something much like the English "one's" (as in "one's ideas are seldom respected")?

I don't know if I'd call it formality, because "oni" is very common in Esperanto, much more common than "one" in English.

I think part of the reason is that Esperanto has other words that can (or must) be used in situations where we'd use "one's" in English, so those other words end up being used instead of "onia'. For example, if "onia" is the object of a sentence, referring back to the subject "oni", we have the word "si", to use, the reflexive pronoun.

The word "ies" (someone's) is another good way to talk about impersonal possession.

For example, it sounds very formal in English to say "One must always bring one's wallet". In Esperanto, that ends up as "Oni ĉiam devas kunporti sian monujon".

You can see how that doesn't use "onia".

Another reason is that if you are over-using "onia", the question becomes, "Why are you being so vague about who you're talking about?". It starts to sound evasive.

And yet another reason is that sometimes it can simply be left out. Sometimes instead of saying, for example, "oniaj ideoj", you can just say "la ideoj", because it's understood through context that ideas belong to someone, they don't pop out of thin air. "onia volo" - that can often simply be "la volo", because someone has to want something, have the will for something, it also doesn't occur in a vacuum.

Thank you for clearing the grammatical fog, Erinja.
I appreciate it.

It could be used proverbally,

'La domo estas onia burgon.'

Except that we don't ever use -n with "estas"

Others 2 exemples, here oni means homoj: (one of them in accusative)

[LISTO]
la malpura aero malsanigas onin (dirty air makes one/people sick)
la vetero multe rilatas kun onia farto (climate has much to do with one's/people's health)[/list]All is correct?