"This is going to help him."
Translation:Esto lo va a ayudar.
I wrote “esto le va a ayudar a él” and it was accepted, but as an alternative it suggested “esto lo va a ayudar” now I am very confused. how can it be correct to use him both as direct and indirect object?
oh and I found this: https://forum.duolingo.com/comment/409409/Esto-lo-va-a-ayudar
That is an example of "Leísmo".
Your answer would be fine in Spain but not anywhere else in the Spanish-speaking world. Everywhere other than Spain "Le" is just the Indirect Object Pronoun meaning "to him/her/it" or "for him/her/it".
You should use "Lo" the Direct Object Pronoun which means either "him or it (masculine)".