This is the 1494th most frequent Swedish word.
kyrka
Church.
Here, 'kyrka' refers to a physical building, used as a noun to name and describe a place of worship followed by an adjective describing its age.
Vi besöker en gammal kyrka varje sommar.
We visit an old church every summer.
In this sentence, 'kyrkan' is definite, indicating a specific church known in the context, used as a noun with an article.
Hon arbetar i kyrkan nära vår skola.
She works in the church near our school.
Here, 'kyrka' is used abstractly, referring to the act of attending or the concept of participation in church activities.