"In an Italian city there is a tower which leans."
Translation:En itala urbo estas turo kiu kliniĝas.
Because you need a relative pronoun -- kiu fulfils that role, but kio does not.
Also, korekta means "correcting", not "correct" (it comes from the verb korekti "to correct (something)" and so korekta has to mean "related to correcting", not "without error"). Try senerara or ĝusta or prava.
Imho both “kiu” and “kio” are relative pronouns. The difference is that “kiu” refers to a noun (here: “turo”) while “kio” could refer to a whole phrase or to a demonstrative pronoun such as “tio” or “ĉio:”
- turo, kiu kliniĝas (noun)
- Ni iris baniĝi, kio estis freŝiga (we went swimming, which was refreshing; “kio” refers to the whole phrase “ni iris baniĝi”)
- Mi ne komprenis tion, kion vi diris (I did not understand [that] what you said)
En itala urbo ekzistas turo kiu kliniĝas.
wrong, less good than estas, or fine here? (I see that 5 years ago someone asked and it’s been upvoted, so I imagine it’s been reported at least once and it still isn’t accepted. But it might just be an oversight, who knows?)
If the answer is “less good”, I’m guessing that might be because ekzisti is more often used with permanent states or with the existential importance of the statement? In an extremely broad gloss: “There truly now exists a tower, in an Italian city, which leans—I know this to be true!” The denotation is fine, but the connotation is all wrong for the prompt.
If the answer is “no, only estas works here; ekzistas does not”, I do not understand.