Los niños van con sus padres a la piscina. In English this means: The kids go to the swimming pool with their parents. "Van" is the verb ir conjugated in the third person of the plural. "Ir" is an irregular verb and it's conjugated as this way:
Yo voy
Tu vas
Él/ella va
Notros vamos
Ustedes van
<u>Ellos van</u> (this is the conjugation used for "the kids")
