it's basically the same spell checker that you'd find on Chrome/Chromium and it's many forks, so the capabilities of each is about as much as you'd think (though I'd argue even Firefox's is kinda meh)
Hi Sylvia, yeah Chrome's native one is pretty limited, doesn't catch grammar or context stuff. I built TypoGuard for that reason, catches more than the built-in checkers across gmail/chatgpt/forms etc