This is the 16558th most frequent Turkish word.
yerde
"On the ground" or "on the floor."
Here, 'yerde' indicates the location 'on the ground or floor'.
Kitap yerde duruyor.
The book is on the floor.
In this sentence, 'yerde' describes the activity happening at 'on the sitting surface of the ground'.
Yerde oturup ders çalışıyordu.
She was sitting on the ground and studying.
This use of 'yerde' specifies the place where the stone is located, 'on the earth or ground'.