"What do their bears eat?"
Translation:Kion iliaj ursoj manĝas?
I still do not know well when I should to use kio or kion, can anyone help me?
To make it more transparent, you can say iliaj ursoj mangxas pomon --> iliaj ursoj mangxas kion?. So when the "what" is done something to, you use the accusative form. That's super logical. Although it wouldn't be if that sentence was passive. Is there a passive in Esperanto? Oh yeah, there's one: you use esti+passive participle in the desired tense of the verb, so Iliaj ursoj mangxas pomon. --> Pomo estas mangxata de iliaj ursoj. An apple is eaten by their bears. La supo estis mangxita. The soup had been eaten. La fruktoj estos mangxotaj The fruit will have to be eaten (will be "doomed" to be eaten).
Basically you only need to know the accusative (is that the name? For the -N ending). In this case the bear is eating something, so this something needs to end with -N.
It is to do with the case. In this example, the statement would be 'iliaj ursoj manĝas (ion)'. The bears are the ebject and the thing that they are eating is the object (accusative), so it has an 'n' on the end. We use 'kion' here because the 'what' is in the place of the thing being eaten. If the question is about the subject, such as 'what it is?' we can say 'kio ĝi estas?' without an 'n'. I hope that makes sense...
Because "their bears" are the subject of the sentence. Compare:
"Kion iliaj ursoj manĝas?" = "What do their bears eat?" = "Their bears eat what?" = "What are their bears eating?"
"Kio iliajn ursojn manĝas?" = "What eats their bears?" = "What is eating their bears?"
Duolingo accepted my answer of "Iliaj ursoj manĝas kion?"
It's nice to know that Duolingo and Esperanto are flexible in word order, even when asking questions.
Why does iliaj need the j to make it plural? Isnt ilia already the plural posessive?
ilia = one thing belonging to multiple people
iliaj = multiple things belonging to multiple people
The person in posession is the subject and the posessed things are the objects (accusative '-n'). The 'j' makes the object plural, not the subject. 'mi havas aferojn' means that there are many things, not many of me
As long as the words are marked for accusative and as noun phrases are unsplit, you can put the sentence in whatever order.
li = him
ili = them
lia = his (thing)
ilia = their (thing)
liaj = his (things)
iliaj = their (things)