Presumably, Sarah Lin was not interested in writing a book where the characters travel from dimension to dimension while still worrying about things like learning the local languages or getting infected by local diseases and dying

So what she said is

"Whenever you go to a new world your body and soul adjust to be able to function there"

Your body adjusts so that minute changes in local physics won't cause all your cells to break down

And your soul adjusts so that whatever the local language is is mapped onto whatever your native language and you just hear it as that

Theo, the protagonist, is...probably an American. He's at least an English speaker

So he hears everything as English

He knows like four other Earth languages so if there ARE multiple languages spoken in other worlds they get mapped accordingly

But sometimes you come across a concept that your native language doesn't have a word for

And in this case the soul translation effect just makes up a weird compound word

Tatians don't have a word for sarcasm

so when Theo says the word to his Tatian friend Nauda she kinda tilts her head

because what she heard was "lyingwit"

But this is a known effect

Anyone who travels to other worlds or deals with outsiders regularly knows about this

Which leads to stuff like

Lalye, a Deuxan noble, just assumes that a barbaric outsider wouldn't know anything about the obligation of nobility to aid their lesseers

but it turns out Theo is familiar with a phrase that describes exactly that

There's just a lot of little moment like this

and it's neat

There's a bit where a guy spends like a full paragraph trying to describe a concept that is like weight but isn't quite the same because weight is fundamentally variable based on local environments and theo's just like "Oh you mean mass"

And they just freeze

totally unprepared for someone to actually know the difference between mass and weight because the sciences as we understand them are not terribly advanced in the Nine Realms