I am guessing most languages have an idiom for the concept of not being able to understand something at all… eg. “It’s Greek to me”.
In Czech it is translated as “It’s a Spanish village”.
Others?
Oddly enough, in German, it would be, “Es ist mir Spanisch,” “It’s all Spanish to me.”
Someone told me that they also say, “wie spanische Dörfer”, “like Spanish villages”, but as IANANative German speaker, my linguistic spidey-sense fails me here as to whether or not it is an actual phrase they use.
Calling Nava!
The idiom is the same in Norwegian: “Det er helt gresk for meg.”
“Me estás hablando en chino.” “You’re speaking Chinese to me.”
That’s one idiom I remember hearing (and using) in Spanish.
Yeah, but what do Greek people say?
The German idiom is usually das kommt mir spanisch vor (this seems Spanish to me); the origin is assumed to be to Carlos I of Spain becoming German emperor Karl V in 1519 and importing alien, Spanish manners to the imperial court.
The village idiom is not “spanische” but böhmische Dörfer (bohemian villages): Das sind böhmische Dörfer für mich = I am ignorant on that subject.
The Russian equivalent is “это китайская грамота для меня” [eto kitayskaya gramota dlya menya], meaning roughly “it’s Chinese writing to me”.
I think French also uses “Chinese” as the referent (“c’est du chinois”).
And also “está en chino,” “that’s in Chinese.”
Catalan uses the same expression, but don’t ask me whether it’s influence from Spanish or what. There’s a lot of commonality like that between both languages.
Generally rather “C’est de l’Hebreu” (Hebrew).
Same for Dominican Spanish.
According to Mighty_Boy, Danes say “sounds like a Russian city”.
Nope. We say “Det er det rene Volapyk” = “It’s pure Volapyk”.
We use the expression “A city in Russia” as a comparison, if there is a subject we know nothing about.
Hey, maybe he forgot his Danish since he came back six days ago. 
Or perhaps he misunderstood my question.
There’s also “тарабарский язык” (Tarabarski language) or “тарабарская грамота” (Tarabarski writing). There’s no such language as Tarabarski, it’s the Russian equivalent of the Greek etymology of the word Barbarian - people whose language sounds like “bar-bar”. Something written in Tarabarski is incomprehensible or cryptic.
Really? I’ve never heard that one. Here it’s always “c’est du chinois”.
Huh, I thought that was regional from where I come from. (North-west coast) Live and learn. Have you lived in other places than Oslo, while in Norway?
Εἶναι γιὰ μένα κινέζικα
(It is like Chinese)
In Japanese, ちんぶんかんぶんだ！(loosely meaning: It’s a curious Chinese story.)
According to this site in Japanese, here are other examples:
French: C’est du chinois.
French: C’est de l’hébreu.
Italian: Per me è arabo.
Italian: Per me è ostrogoto.
Italian: Parli turco.
Spanish: Me suena a chino.
German: Das kommt mir Spanisch vor.
German: Das sind mire böhmische Dörfer.
Dutch: Dat is Hebreeuws voor me.
Danish: Det ere det rene volapyk for mig.
Russian: для меня это китайская грамота
Polish: To dla mnie chinszczyzna.*
Polish: Siedziem jak na tureckim kazaniu.
Hungarian: Nekem kínaiul van.
Finnish: Se on minulle hepreää.
Czech: To je pro mne spanelská vesnice.*
Here’s a breakdown:
“Greek” used by speakers of: middle Latin, English, Portguese, Norwegian
“Chinese” by French, Spanish, Russian, Hungarian
“Hebrew” by French, Dutch, Finnish
“Spanish” by Dutch, Czech
“Turkish” by Italian, Polish
“Dutch” by English
“Czech” by German
“Arabian” by Italian
“Volapük” by Danish
“Ostrogothic” by Italian
Yes. In Danish the letter “y” has replaced the German “ü”, but it represents the same sound.
In regard to the OP, we could also say “det er kaudervælsk” = “it is kaudervælsk (to me)”. According to my etymological dictionary “kaudervælsk” breaks down to:
“Chur” - the name of a Swiss town + “Welsh” - i.e. Celtic.
Strange.