This activity should help the student become more familiar with the indirect object pronouns (IOP). They should also remember that we can't use the IOP and another direct object phrase in the same sentence. This is only possible when the direct object phrase has a pronoun: a ella, a él, a nosotros, a ti, etc.

Ejemplo:
Yo no lo conozco a mi jefe. (Incorrecto)
Yo no lo conozco. (Correcto)
Yo no lo conozco a él. (Correcto)