"L-am văzut pe Daniel întrebându-i pe bunicii săi despre mama."

Translation: I saw Daniel asking his grandparents about my mother.

[JamesTWils]

Since this is clearly "the mother," could that also be interpreted as "his mother"?

[potestasity]

Actually, to me at least, it sounds more like it could refer to the speaker's mother. I'd say "[...] despre mama sa." if I were to refer to his mother.

[odt5]

Still seems ambiguous to me. Is "his mother" acceptable? That's how I read it at first glance.

Using the same construction in Spanish or Italian, "his mother" would be the implication IMO.

[nickbii]

"His mother" is definitely not accepted. "The mother" may be. I'll have to try it nxt time I'm doing this lesson.

[whereisalice]

again, how is it "my mother" when there's no noun at all

[ElenaLivia1]

The pronoun is implied in this case. If it were about Daniel's mother, then it would be "despre mama SA/LUI. If it were about someone else's mother (not Daniel's or the speaker's) it would be "despre mamă". When Romanians talk about their own parents, they drop the possesive pronoun (sa, lui, ei, lor ecc.) and use the articulated form of the noun. Example: Am fost cu mama la plajă = I went with my mother to the beach. If it were about someone else's mother the sentence would be: Am fost cu mama EI la plajă = I went with HER mother at the beach. In this case you cannot lose the pronoun.

It is not wrong to use the possesive pronoun (mama MEA), but it can be left out in this case.

[Cihan15170820]

Thanks for the explanation, it was a big question for me to distinguish between them.

[houdmoed]

Why not 'his mother'?

[houdmoed]

Forget this question. Already been answered

[olb38]

Why we use "pe" in costruction like this ? I am asking because fir me "pe" = "on" - and it seems unnatural (for me)

[f_monts]

It's used for the object of the predicate:
Eu TE am văzut PE TINE
"te" and "pe tine" means the same thing (when used both it's to make the concept stronger)