Learn Finnish: Kuraattori seisoo vitriinin edessä. - The curator is standing in front of the display case.

Finnish doesn't have articles like "the" or "a", so it uses word order (information structure) instead. The beginning of a Finnish sentence is the Theme: the old, established information. Because Kuraattori is placed first, it's treated as already known to the listener, translating to "the curator." The end of the sentence is the Rheme (new information), revealing where they are.

If I wanted to say "A curator is standing in front of the display case", how would I change this sentence?

You would flip the sentence to a Location-Verb-Subject word order: Vitriinin edessä seisoo kuraattori. By establishing the location first (making it the known Theme) and moving kuraattori to the end (the Rheme position for new information), the curator becomes a newly introduced entity, translating to "a curator."

Since we are talking about a location, why doesn't the word vitriini take a location ending like -ssa?

Because the exact spatial relationship is handled by the postposition edessä (in front of). Notice that the postposition itself actually carries the locational ending (the inessive -ssä). As a quick refresher: when using most postpositions in Finnish, the noun preceding them must be in the genitive case, which gives us vitriinin.

What if we started the sentence with the verb: Seisoo kuraattori vitriinin edessä?