This is the 386th most frequent Swedish word.
sätter
"Sets" or "puts".
In this sentence, 'sätter' is used as the verb meaning 'puts or places', indicating the action of positioning the books on the shelf.
Hon sätter böckerna på hyllan.
She puts the books on the shelf.
In this example, 'sätter sig' is a reflexive construction meaning 'sits down,' describing the action of taking a seat in the chair.
Han sätter sig i stolen för att läsa.
He sits down in the chair to read.
Here, 'sätter' is used metaphorically to mean 'set or instigate,' highlighting the initiation of a process or idea.