indirect object pronoun

Question

I was marked wrong for answering "Nosotros LES damos juguetes a nuestros hijos" instead of just "damos" I thought that the indirect object pronoun HAD to be used. What am I missing? When should I be using it?

Thanks.

Accepted Answer

Hola Peter
This is a complex bit of grammar but here is the link to what R.A.E (Real Academia Española) says about this particular repetition of the indirect object pronouns. Sorry it's all in Spanish (I couldn't find any article in English about this specific case)- If you go straight to bullet point 5, called Duplicación de complementos: coaparición del clítico y el complemento tónico -  It is in 5.2.a  that you have similar examples at the beginning of that point where you can see that le-les are optional. 
I hope that helps.
Saludos
Inma

Answer

Hola Peter
Your answer "les damos" using the pronoun is absolutely correct. It's not compulsory to use "les" but the repetition of the indirect object in this case is natural. I marked as correct your answer in the system. 
Saludos
Inma

Answer

Thanks for the reply. During my studying I was sure that the indirect object was not optional and had to be used. Please could you confirm that to use "les" in situations like this is NOT compulsory and can be left out?