(it's) (all) Greek to me

cliché This might as well be a foreign language, because I don't understand it at all. The phrase comes from Shakespeare's play Julius Caesar. Can you make sense of these instructions? It's all Greek to me! A: "Can you understand this error message?" B: "Sorry, Greek to me. You'd better ask one of the programmers." I thought I had a handle on Foucault's theories, but this concept of his is all Greek to me.

that's (all) Greek to me

cliché That might as well be a foreign language, because I don't understand it at all. The phrase comes from Shakespeare's play Julius Caesar. A: "I've got some tax forms you need to fill out." B: "Would you mind doing them? That's all Greek to me!"

Greek to me, it's/that's (all)

It is completely unintelligible; I don’t understand. This term, used by generations of schoolchildren, was coined by Shakespeare in Julius Caesar (1.2), where the conspirator Casca says of Cicero’s speech, “For mine own part, it was Greek to me.” In the play Cicero actually spoke in Greek, in order to prevent some people from understanding, but the term soon was transferred to anything unintelligible and has been so used ever since.