When an English speaker doesn't understand something, he would say "It's all Greek to me." But have you ever wondered about the origin of that phrase? Why Greek? Why not, say, Urdu or Aramaic?
1. The Origin of "It's All Greek To Me"
According to Harry Oliver's Flying by the Seat of Your Pants: Surprising Origins of Everyday Expressions, it comes from the latin phrase Graecum est, non legitur or Graecum est, non potest legi (It is Greek; it cannot be read). Medieval Latin scribes in monasteries would write that phrase if they had trouble translating Greek alphabet and language, which was dwindling in use by the Middle Ages.
The phrase probably entered modern English usage when William Shakespeare used it in his 1599 play The Tragedy of Julius Caesar. Here it is in Act 1 Scene 2:
Cassius: Did Cicero say any thing?
Casca: Ay, he spoke Greek.
Cassius: To what effect?
Casca: Nay, an I tell you that, I'll ne'er look you i' the face again: but those that understood him smiled at one another and shook their heads; but, for mine own part, it was Greek to me. I could tell you more news too: Marullus and Flavius, for pulling scarfs off Caesar's images, are put to silence. Fare you well. There was more foolery yet, if I could remember it.
In this context, an educated and wealthy aristocrat in the Roman Republic should be able to read and speak Greek. Casca, who speaks fluent Greek, is probably just playing dumb because he doesn't want to repeat a remark that is unflattering to Caesar.
2. Well, what do the Greeks say?
Obviously, when a Greek doesn't understand something, he doesn't say "It's all Greek to Me." Rather, he says, Αυτά μου φαίνονται κινέζικα, or "This strikes me as Chinese."
3. It's all ______ to me
That brings up an interesting question: what language is deemed the most incomprehensible and therefore most worthy of the phrase "It's all ______ to me" in various countries? Wikipedia and Omniglot have the list of the idioms.
Mark Liberman of Language Log distilled the info into this nifty graphic:
(Liberman has an updated version here)
4. From Greek to Gringo
The word "gringo," which is a Spanish slang to denote foreigners or non-native speakers of Spanish, comes from the phrase "hablar en griego" (or speaking in Greek). You can see how the phrase accusing someone of not being intelligible because he's speaking Greek eventually evolved into a slang for foreigners.
5. Coming Full Circle: Greeking ... in Latin!
When web or print designers create a mock up of a design with a block of text, they often put in place dummy text in the layout before the actual text is available. This process is called "greeking" and the most commonly used placeholder text is Lorem Ipsum, which is actually Latin, not Greek.
http://www.mcm.edu/academic/depts/pubhist/Uniforms.htm