"We are looking at the animals that live in Denmark."
Translation:Vi kigger på de dyr som bor i Danmark.
I am also confused about why it is "de dyr" instead of "dyrene". My guess would be that the relative clause ("som bor i Danmark") behaves the same way with a noun as an adjective would, and therefore requires the separate definite article rather than the usual suffix...?
This is more an irregularity in English. It would probably be "more correct" saying "..which live in Denmark" as this corresponds closer to the Danish word som, but in English you can also say "..that live in Denmark". Rule of thumb is, if you can substitute "that" for either "who/which" in English and the meaning doesn't change, then use som
Google translate lists 'som' as the pronoun 'that', so maybe in this sentence 'that' could be considered a pronoun? (If it helps, Google also lists it as the pronoun 'who'. Swapping the two words gives "We are looking at the animals who live in Denmark" which I'm pretty sure means the same thing in English, just a little odd to say.)
"Hvilke" is a question word in Danish, so it wouldn't be used like a pronoun like "som" is in this sentence.
"Hvilke bøger kan du lide at læse?" Which/What books do you like to read?
"Jeg har to slags æbler, hvilken kunne du tænke dig?" - I have two kinds of apples, which would you like?"
Ah ok thank you. Now I understand. I was coming from the german grammar. Here the german words "welcher, welche, welches" as corresponding words to "hvilken, hvilke, hvilket" cannot only be used as an interrogativ word in a question sentance or question subordinate clause but also as demonstrative pronoun / conjunction at the beginning of an other subordinate clause.