This is a regular verb. It follows the conjugation pattern of the verb hablar.
PresentPresente
Me fascina cómo piensa esa científica.
I’m fascinated by how that scientist thinks.
PreteritePretérito indefinido
La exposición nos fascinó.
The exhibition fascinated us.
ImperfectPretérito imperfecto
De niño, le fascinaban los dinosaurios.
As a child, he was fascinated by dinosaurs.