"There is only one church in the city."
Translation:Det finns bara en kyrka i staden.
"Det är bara en kyrka i staden" was not approved. Does it have a different meaning or is it simply something that is never uttered?
It has a different meaning. Good rule of thumb is that "är" means "is" and "finns" means "exists". I would say that saying "Det är bara en kyrka i staden" would convey about the same meaning as saying "It is only a church in the city".
It's not exact, but often "i" translates to "in" and "på" translates to "on". If you wrote "prästen är på kyrkan" I'd assume he was up on the roof.
"Stan" is colloquial. You use it in everyday language, such as "Jag ska till stan" ("I'm going to the city") och "Jag bor i stan" ("I live in the city"), and often in contrast to "the country" ("landet"), whereas "staden" often describes one specific town.
You must mean ende, which is the masculine form of enda. (The masculine form of adjectives is totally optional, in some regions it is never used). It is used as a definite adjective in constructions like det var enda gången 'it was the only time' or du är den enda för mig 'you are the only one for me'. It shows up in the hint here because there is a hint somewhere else saying that "the only one" can mean den enda/ende, like in my second example, but it's not the same kind of 'only one' here.
Wrong grammatical gender. You have to learn the gender (ett- or en-noun) with every word.