This is a regular verb. It follows the conjugation pattern of the verb hablar.
PresentPresente
Yo me alegro de verte otra vez.
I am glad to see you again.
PreteritePretérito indefinido
Mi padre se alegró al ver mis notas.
My father was happy when he saw my grades.
Present SubjunctivePresente de subjuntivo
Espero que te alegres con esta sorpresa.
I hope you are happy with this surprise.