Don't we always need an indirect object pronoun?

Question

Which is the correct sentence for "We've already mentioned it to the boss."?What about "Ya se lo hemos mencionado al jefe????Ya hemos lo mencionado al jefe.Ya lo hemos mencionado al jefe.Ya hemos mencionado al jefe lo.Ya hemos mencionádolo al jefe.

Answer

Hola AllisonThere are two possible answers for "We've already mentioned it to the boss."1. Ya se lo hemos mencionado al jefe.2. Ya lo hemos mencionado al jefe.The "se" in the first one is "to him" [it should be "le" but "le" becomes "se" if followed by "lo/los/las"]. So we can repeat the indirect object in the sentence if we want to. [se + al jefe]However the first indirect object pronoun is not compulsary, so we can just omit it. This would be sentence 2.I hope this helps.Un saludoInma