This is an irregular verb. It follows the conjugation pattern of the verb llegar.
PresentPresente
Yo pago el alquiler el primer día del mes.
I pay the rent on the first day of the month.
PreteritePretérito indefinido
Ellos pagaron la cuenta entre todos.
They paid the bill between all of them.
ConditionalCondicional
¿Tú pagarías tanto por unos zapatos?
Would you pay that much for a pair of shoes?