Yes, this is something we certainly need to adjust, and before we can do things like localization. Typically we do try to keep things to American English, though being human I do slip up once in a while and use everywhere else in the world English instead.
As Vapourfire mentioned, we do have a tooltip hunt channel on the forum, where you can post references to any incorrectly spelled, worded, or just ‘wrong’ tooltips, or you can use the bug report forum as well - though I think we are aware of most instances of this, we just need to commit to the hunt to chase them down and fix them all, which would likely happen before we start localization efforts.
Edit: sorry, I left out part of the response I meant to include. For more reference regarding these changes - In Last Epoch some tags are written manually by hand, while others are generated automatically by the system based on attached tags. This is one of the challenges we have regarding localization, and mention in the FAQ, and something we’re already working on fixing. So I don’t at all mean to be dismissive of these discrepancies, we are working on them, just due to the nature of how descriptions work make it a larger task than it may appear at the surface.