Double angle quotation marks to indicate translated language in fiction?

I’m writing a story and I want the reader to know certain characters are speaking a “lost” language, but I don’t really want to invest the time in actually creating the language, and I really don’t want to just write gibberish. I seem to remember seeing double angle quotation marks (« and ») used to indicate that certain dialogue is included translated from another language. Would this be proper, or am I just imagining things? Failing that, how could I do this?

However you want. I used asterisks to indicate telepathic dialog in two novels; no one ever made a comment.

There’s no “right” way. Pick a convention and stick with it. And what you’ve chosen are used as quotation marks in some languages anyway, so it’s a reasonable n choice.

Sounds good, thanks.

For what it’s worth, those symbols are called “guillemots”. Which I only know because I used to program my HP calculator, which used those where most languages would use {curly braces}.

Wikipedia says “guillemot” is a kind of auk, and the punctuation is “guillemet.”

They’re just the standard way to make quotes in many languages, most notably in French.

Other quotes exist in other languages. For example, German (and other languages) uses ones similar to English, except that the left quote becomes the right quote, and the new left is both facing outward and on the bottom „like so.“

I think for your purposes guillemets, asterisks, italics, Esperanto, etc. would all be cromulent conventions for simulating a foreign language.

I mostly encounter this in comic books. Albeit, they usually just use single brackets.

I have also seem italics, bold and/or all caps used to denote other languages. I think your << >> option would probably better than any of those three, though.

I’ve seen < and > used several times, for both foreign and telepathic speech.

You could do that, or you could use an unusual font to indicate a different language (or a particular speaker).

In Avatar, the Na’vi are subtitled in Papyrus

IN TERRY PRATCHETT’S BOOKS, DEATH SPEAKS IN SMALL CAPS

In Pogo, various characters speak indifferent fonts.