Nora and the Last Language by IOAKIM IOAKIM

Nora has always heard things other people cannot. Sounds that arrive between sleeping and waking. Words in no language she has been taught — words that taste like iron, smell like rain on stone, and hum in her back teeth when she speaks them aloud. Her mother calls it imagination. Her teachers call it distraction. The man who has been following her for three weeks calls it something else entirely.
His name is Aldric. And what he tells Nora in a library that exists between two buildings that have no business having space between them is this: she is the last keeper of Veth — the oldest language in existence. Not a language of names and descriptions, but the language the world uses to hold itself together. Every word forgotten makes something in the world less real. Every word remembered keeps something alive.
But someone else has found her. A man named Cael who believes, with absolute sincerity, that the language holding the world together is also the language holding it in place — and that if Nora forgets, the world will finally be free.
Nora must decide what she believes. And she must decide it alone, in the rain, with everything depending on a single spoken word.
A rich, literary, deeply atmospheric fantasy for readers aged 10-13 who are ready for stories that do not offer easy answer