First, identify the indirect object in each sentence. then, replace the indirect object with an indirect object pronoun.
1. cocina una hamburguesa a tus hermanos
2. compra un auto a tu amigo.
3. escribe una carta a tu padre.
4. limpia el pelo al perro.

When could you attach the direct object pronoun to an infinitive verb? a: when an infinitive verb follows a conjugated verb. b: when an infinitive verb ends in a question. c: when a stem-changing verb ends in a question. d: when a stem-changing verb follows a conjugated verb.