system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: How did philologists (people who study ancient languages) learn to decipher ancient texts, if there was no understandable translation available upon discovery?

To me it seems like this would be similar to trying to learn to read Chinese with absolutely no access to any educational materials/teachers.
gpt
Two ways: 1 finding cases where it's translated into another language, that's why the rosetta stone was such a big deal, it had several languages all saying the same thing on it, one of which was ancient greek, which we already knew so they could use that translation to work backwards.

The other way, is what another commenter said, you look at where words pop up, if you keep seeing a word show up on things at greengrocers and farms, it's probably a plant of some kind.

And once you know a few words it starts to become possible to work out the others through context.