This is an irregular verb. It is a model verb.
PresentPresente
Yo ando media hora cada mañana.
I walk for half an hour every morning.
PreteritePretérito indefinido
Ayer anduvimos por el centro toda la tarde.
Yesterday we walked around downtown all afternoon.
ImperfectPretérito imperfecto
Mi abuelo andaba despacio por el parque.
My grandfather used to walk slowly through the park.