In Spanish, we use object pronouns (pronombres de objeto directo) such as lo and indirect object pronouns (pronombres de objeto indirecto) such as le in place of nominal direct and indirect objects. In the Table below is shown the Spanish direct and indirect object pronoun forms.
If the direct and indirect object pronouns are used together in a sentence, the indirect object pronoun goes in front of the direct object pronoun. On the other hand, the indirect object pronouns le and les change to se when followed by the direct object pronouns lo, la, los and las.
In this way, we can solve this problem as follows:
Q11. Nosotros vendemos el pan a las personas.
Nosotros se los vendemos.
Q12. Yo compro la computadora para mi mamá.
Yo se la compro.
Q13. Usted da las cartas a mí.
Usted me las da
Q14. Ella compra la manzana para Javier.
Ella se la compra
Q15. Ellas muestran las blusas a ti.
Ellas te las muestran