This is an irregular verb. It follows the conjugation pattern of the verb pensar.
PresentPresente
Siento a los niños cerca de la ventana.
I seat the children near the window.
PreteritePretérito indefinido
Sentó a su abuela a la mesa.
She seated her grandmother at the table.
FutureFuturo
Sentaremos a los invitados en el jardín.
We will seat the guests in the garden.