Some words doesn't exist in a different language in one only word and need to be explained somehow. Can you share any?
In Spanish (from Spain) I know these ones, some of them really curious that doesn't exist in English...
-'Tutear' (verb): addressing someone in an informal way. This makes sense in my language since there's a variant in the second person (you) used formally when addressing old (or older) people, higher rank, or simply when we meet someone we don't know even with similar age. (To be honest I hate it when childs address me like that)
-'Empalagar' (verb): when you eat something which is extremely sweet for your taste that makes you sick. Used also as an adjective.
-'Sujetavelas' (noun): it's like an unwanted extra person who goes out with a couple (yeah.. annoying)
-'Estadounidense': Native from the USA. This is actually the most shocking to me and I guess that's why they call themselves Americans or North Americans but can be controversial for other citizens from the American continent. In this way I'd say this confusion is caused by the lack of this simple word.
-'Entrecejo' (noun): the space between the eyebrows (awful word btw)
-'Estrenar' (verb): Use / wear / perform something for the first time (I believe this words exists in your language, no?
-'Friolero' (adj): someone who is sensitive to the cold weather or dislike it.
I might be wrong and some of these words do exists in English, in such case let me know.
Inversely there're English words that doesn't exist in my language like the last one I learned; 'jaywalking'. I'd have never believe this word could exist in any language :D