This is a regular verb. It follows the conjugation pattern of the verb comer.
PresentPresente
No comprendo esta lección de matemáticas.
I don't understand this math lesson.
ImperfectPretérito imperfecto
De niño, no comprendía a los adultos.
As a child, I didn't understand adults.
Present SubjunctivePresente de subjuntivo
Espero que comprendas mi decisión.
I hope you understand my decision.