In Spanish there is a rule that gender defers to MALE when a sentence is neutral. At DUO, it usually defers to FEMALE. This is what I have noticed. No big deal, as it's neutral, so either HER or HIM. It could even be IT if you were referring to an organizational body, as in " I am going to ask IT an important question."
SariahLily, you wrote "technically not incorrect." My native Spanish speaking college professor said that if a spanish sentence has an indirect object it should also have an indirect object pronoun. I just did a search on that and found verification at the link below. Except they say must instead of should.
Hmm, I was going to simply say, "I stand corrected," but that link contradicts itself. It gives "Él compró unos regalos para nosotros" as an example, then later says you can't just have the prepositional phrase.
It might indeed be necessary to add "le" when the indirect object is the third person (it certainly sounds weird to me without it). But "nos compró.....para nosotros" feels needlessly redundant to me.
Can you ask your professor about "Él compró unos regalos para nosotros" please? Also, where is your professor from? (I'm just curious.)
Well, you can't know. Le means both him, her and formal you. If you want to emphasize that you're doing something to a male person you add a él in the sentence or if you want to emphasize you're doing it to a female person you add a ella.
These sentences are taken from mid-conversation so you can't know which person you're talking about. But if we could hear this conversation from the start or you're the one engaging in the conversation with someone in spanish then you would know whether you're talking about a male or a female person.