Kiel oni uzas povi kun la pasivaj participoj?

mi bedŭras pro uzi la anglan kiel ekzemplon, sed tio estas la sola lingvo, kiun mi parolas nun:

I could be eaten by a bear
I could have been asked to go to the park.
Ktp.


Ĉu oni iumaniere uzus “”povintus”?.... Mi ne scias....

Dankegon

Mi povus esti manĝata de urso.
Mi povus esti petita iri al la parko = Oni povus peti min iri al la parko.
Estas same, kiel en la angla - oni ne uzas 'povi' en pasivo.
Sed vi povas uzi aktivon kun 'oni' ('they') anstataŭ aktivo.
En pasivo, anentu uzi -ITa aŭ -ATa.

The best translations are ones that sound natural in the target language. In some cases where it is natural to use a passive in English, it may be more natural in Esperanto to use the active.

Also this avoids having to choose between -ata, -ita, -ota for the passive.

I could be eaten by a bear. This seems most plausibly to be concerned with a real possibility. Eble urso manĝos min. But if the conditional seems more appropriate, then urso manĝus min (se .. ) or povus esti ke urso manĝos min.

I could have been asked to go to the park.The conditional may be appropriate. Context will change the translation.

Vi povintus demandi min ĉu mi ŝatus iri al la parko. (you could have asked me)
Povas esti ke oni petis min iri - mi ne plu memoras. (I could have been asked)

Nala,

The English language has a very strict word order, which on the one hand has enabled stripping grammatical cases and prepositions, on the other hand has carved the order in stone. In all other cases but direct questions the word order is subject-verb-object (SVO) in English.

But any language gets dull, if there is only one word order to use. Therefore in English one uses a lot of passive voice in order to have variations.

      I paint the house → The house is painted by me.
      A taxi hit an old lady → An old lady was hit by a taxi.
      A bear could eat me → I could be eaten by a bear.

As Sudanglo points out the best translations are ones that sound natural in the target language. Because the word in E-o is more liberal than in English, there is way less need to use that kind of passive voice in E-o.

      Oni farbas la domon. (ok, the actor gets lost)
      Estis taksio, kiu puŝis maljunan virinon. (emphasis on taxi done by having a main and a subordinate clause)
      Eble urso manĝos min. (the possibility is expressed by another word)

One of the hard things to grasp in E-o is, that the -us form is timeless. Thus a sentence in past conditional in English

      I would not have done an error, if they had told me the truth.

can be translated in a couple of ways in E-o

      Mi ne farus la eraron, se ri antaŭe dirus al mi la veron.
      Mi ne estus farinta la eraron, se ri (antaŭe) estus dirinta al mi la veron.

of which the first one is more natural. Note, that in that sentence only "antaŭe" reveals, that it's about past tense. While theoretically a form "farintus" is possible, I strongly recommend to stay away from such "-intus" constructions.

As a final remark note, that the -us form is usually translated as conditional, while a more correct name would be imaginary mode (imaga modo) (PMEG by Bertil Wennergren uses that).

This mode can be used:
- for non-real situations: Se mi estus sana, mi laborus (but I'm sick now)
- for imaginary situations: Se li nur estus iom pli bela! (but he is not)
- to make the T-V distinction: Ĉu vi povus doni al mi la buteron? (Können Sie bitte mir die Butter geben?)

In many cases English "could" and "should" do not express those situations.

"Ri" is experimental. Only 4 hits in the Tekstaro, and those from a single and recent source.

On the other hand 600 hits for -intus from a variety of sources dating back some 60 years.

[ By the way, if it 's that important to conceal the gender (and how often is that the case?) why not use ŝli, which any Esperantist can guess the meaning of, rather than the opaque "ri".]

One of the hard things to grasp in E-o is, that the -us form is timeless.(really?)
Se mi estus sana, mi laborus (but I'm sick now)
Se li nur estus iom pli bela! (but he is not)

It is true that the situation will determine whether the -us is seen as applying to the present or the future. But In neither of those examples would any Esperantist naturally assume a past reference.

Mi ne farus la eraron, se tiu homo (persono) antaŭe dirus al mi la veron.

Less politically correct, but more compliant to La Fundamento.

Dankegon al ĉiuj por la respondoj

[I don't use "ri" to conceal the gender, but rather to avoid emphasising the gender as the traditional pronouns do, but let's not hang ourselves on this.]

When it comes to mallongigitaj kunmetitaj verboj (i.e. -antas, -ontis,… -antus, -ontus, -intus instead of esti + participo), Wennergren states in PMEG:

PMEG:
Zamenhof neniam uzis tiajn mallongigitajn formojn, sed ili estas tute logikaj. Bedaŭrinde ili estas en la praktiko tre malfacile kompreneblaj. Vorto kiel legintos enhavas ŝajne tro multe da informoj en tro kompakta formo. La normalaj kunmetitaj formoj kun esti estas pli taŭgaj en tiuj maloftaj okazoj, kiam oni ne povas uzi ordinarajn simplajn verboformojn (legis, legos k.t.p.).

I couldn't agree more. Such forms are too compact. You need to stop to decipher the meaning, which means that your reading slows down or you likely miss the next sentence in speech.

I find the timelessness of the imaga modo a little bit puzzling. Yes, it's true, that you can more or less easily decipher from the context, whether Se mi estus sana, mi laborus means I'm sick now or I was back then and therefore I can't or couldn't work. But once again do we have to pause to decipher?

That there is to much information packed into a word like legintos is a very weak argument for a language like Esperanto. You might just as well argue that you should avoid, say, 'malsanulejo' (4 elements) as it is too dense.

However, there is no need for any arguments. The Tekstaro shows that forms like -intos, -atis, -antos, -atis etc.just haven't caught on - in contrast with -intus which has..

I suppose an argument against mi devintus legi might be that it melds two possible meanings.

Mi devus esti leginta la kontrakton (mi nun konstatas mian eraron)
Mi estus devinta legi la kontrakton (sed tiam mi ne havis tiun devon).

Mi ilustras angle.

Sorry I was late, I should have caught the earlier train
To get there on time I would have had to catch the earlier train.

I admit, that I got slightly heated. My apologies.

There are a few of reasons, why those forms haven't caught on. As Wennergren states, Z never used those. While malsanulejo has four elements, we have grown to it, so that you usually don't have to decipher it. Those mallongigitaj kunmetitaj verboj are so seldom encountered, that in order to understand those we have to decipher them, causing the pause I mentioned. Add to this the dusenceco you mentioned. And finally as has been stated a couple of times English "could" and "should" do not always mean a fictitious or imaginary situation, where as the imaga modo must do (unless used to make the T-V distinction).

Nala, to bring this back onto the track, use of active verb is in most cases a preferred solution or if you really need passive voice, use oni. When it comes to could/should/ought, think twice, do they really denote a fictitious or imaginary situation thus justifying the imaga modo.

This has been discussed several times on Duolingo. I try to find some postings.

Addendum:
At least these are in Duolingo: "Should have", "Ili estus devintaj pagi" and "Li ne povintus scii, ke ni ne estis tie." In all cases read the comments by Salivanto.