Here from a survey of translators are the top ten most difficult to translate words.
THE TEN FOREIGN WORDS THAT WERE VOTED HARDEST TO TRANSLATE
1 ilunga [Tshiluba word for a person who is ready to forgive any abuse for the first time; to tolerate it a second time; but never a third time. Note: Tshiluba is a Bantu language spoken in south-eastern Congo, and Zaire]
2 shlimazl [Yiddish for a chronically unlucky person]
3 radioukacz [Polish for a person who worked as a telegraphist for the resistance movements on the Soviet side of the Iron Curtain]
4 naa [Japanese word only used in the Kansai area of Japan, to emphasise statements or agree with someone]
5 altahmam [Arabic for a kind of deep sadness]
6 gezellig [Dutch for cosy]
7 saudade [Portuguese for a certain type of longing]
8 selathirupavar [Tamil for a certain type of truancy]
9 pochemuchka [Russian for a person who asks a lot of questions]
10 klloshar [Albanian for loser]
†¢ THE TEN ENGLISH WORDS THAT WERE VOTED HARDEST TO TRANSLATE
My take: It’s rather common to hear that language determines thought and thus if a language has no words for a concept then that concept can’t really be understood by a speaker of that language. I find this theory difficult to believe (perhaps it was first proposed in a language other than English.) If the theory is true, however, I would like to learn the language where “spam” is untranslatable.