Swedish uses much more precise words to describe relations. I came across a sentence in English that is almost completely untranslatable without more context: "One of my grandfathers really likes strawberries, but my other grandfather hates them".
This is because Swedish uses different words for the parental and paternal grandparents. If you speak Swedish, try to translate the sentence above. It's not easy.
What other languages have this problem? Even Norwegian and Danish have words for this I think?