All the time, 80% of my music collection is in languages I don't speak (English or Spanish)
While typing this message I'm listening to Russian metal
• Do you like listening to songs that are sung in a language you don't speak fluently? - yes I do, lots of the music I like is from Europe, and even if some bands do have songs in English, the ones in their native language just sound so much better in my opinion.
• If so, do you make an effort to know the lyrics in your own language, or do you just listen without knowing because it sounds cool? - I mainly listen to them because the language just sounds cool with metal music, I do try and sing along at times, I'm only interested in learning what the song is about, or if possible find a translation of the song
• Which languages? A quick list:
Arabic: Al Namrood, Narjahanam - نار جهنم
Danish: Fjorsvartnir
Dutch: Heidevolk
Estonian: Metsatöll
Faroese: many of Týr's songs
Finnish: Korpiklaani, a few Ensiferum songs
German: Menhir
Georgian: Ennui
Icelandic: Skálmöld
Latvian: Skyforger
Lithuanian: Obtest
Japanese: Gotsu Kotsu Totsu - 兀突骨
Norwegian: Ásmegin, many of Darkthrone and Gorgoroth songs
Romanian: Bucovina
Russian: Arkona - Аркона
Slovakian: Prarod
Swedish: Vintersorg
Thai: Wiplas - วิปลาส
edit: forgot to mention, I'm always searching for more metal bands from other countries, that sing in their own language, I don't mind if they sing in English but at least have songs that they sing in their native language too.
• If you don't, is it because you don't know the lyrics in your own language? - this won't apply to me.