... at least, post facto.
A grad student named Ben Schmidt (I think), has applied Bayesian statistics to film and tv transcripts, comparing them to books of various periods, to help determine which phrases are most likely anachronisms.
Spotting anachronisms can be fun if you're into that sort of thing, as when Downton Abbey's folks talk about a "steep learning curve." And it's fun to learn that "snipers" didn't exist in Lincoln's time; they were "sharpshooters."
It's also instructive, because when there weren't words for things, sometimes there weren't the ideas for them, either. Though sometimes, you discover that the ideas, and the words, are very old indeed. For example, "colonialism" seems like a modern, snippy word. But it is what the Romans practiced, and "colonia" is their word for a, well, colony of Romans they stuck in some patch of land they wanted to keep.
Anyway, go have some fun at Prochronism
and see what a brute force linguistic approach can do for your appreciation of a period piece.
My rule in writing period dialog is to make the characters sound like they are talking in the modern era -- no "what hath thou" nonsense -- because everyone is modern when they're alive. The ancient Greeks didn't speak ancient Greek, they spoke the very latest up-to-date Greek of the time. And you can be earthy. "Son of a bitch" has to be at least ten thousand years old (depending on when you believe canis familiaris was domesticated). Just, keep modern slang out of it. Can't have those ancient Greeks saying, "I am so totes over him."