I saw a sentence
Kien Adamo volas iri?
Here I guess the 'n' in the 'Kien' makes 'to where' rather than
Don't let the English language confuse you. "where" has (at least) to meanings in English, which have to be distinguished by context:
- location ("At what place?")
- destination ("To what place?"), sometimes expressed as "where to" (almost never "to where"), but often just also as "where".
Is it the same 'n' as in the objective of a verb, like "Mi manĝas
That depends on what you consider "the same". It's the same letter (lower case N). It's there due to accusative case in both sentences. But the reasons for using accusative a different:
- In "Kien Adamo volas iri?" it's an accusative marking a location ("Kie") as a destination (of the movement "iri" itself of of its direction.)
- In "Mi manĝas pomon.", the accusative marks "pomo" as the direct object of the action "manĝi".
If there is no n like 'Kie Adamo volas iri?', does it make different
meaning or is it syntactically incorrect?
It'd be syntactically and grammatically perfectly correct, but indeed have a different meaning: It'd be a question about where (at what location) the movement "iri" takes place, rather than about its direction or destination.
Examples for location:
- Kie Adamo volas iri? (At what place does Adamo want to go?)
- Li volas iri en la strato. (He wants to go on the road / street. That's where the going takes place, not what its destination is.)
- Kie Sofia marŝas? (Where (at what place) is Sofia walking?)
- Ŝi marŝas en la montaro. (She walks in the mountains. (Not through tunnels, probably, but in a mountain range area, e.g. in the Alps.))
Examples for destination:
- Kien Adamo volas iri? (Where(-to) does Adamo want to go?)
- Li volas iri al Torino. (He wants to go to Turin. "al" is already a preposition of destination/direction rather than of location, so no accusative here.)
- Kien Sofia marŝas? (Where(-to) is Sofia walking?)
- Ŝi marŝas sur monto-pinton. (She walks towards (or onto) a mountain top.)