"My grandmother is giving her fruit."
Translation:Moja babcia daje jej owoce.
The sentence has double(triple?) meaning.
- Grandma is giving her (Alice) fruit. - Babcia daje jej owoc/owoce
- Grandma is giving her (own) fruit- Babcia daje swój owoc/swoje owoce.
- Grandma is giving her (Alice's) fruit- Babcia daje jej owoc/owoce
Swojego would be only for masculine animated singular nouns.
Ah. The use of swojego must have made it wrong. I presume they would have marked it correct if i had used swoj. I just would be frustrated if it had to be jej instead of a swo- form because I thought I understood the use as you explained it above (what I have not learned is when to use swojego vs. swoj vs. swoje, etc.)
"Who is grandma then giving the fruit to?" - I could think of an English example that isn't too contrived in my opinion. "The charity sale is coming up. Uncle Peter is contributing some of his wooden toys, you're bringing knitted scarves, Grandma is giving her (preserved) fruit." but obviously I don't know if it makes sense in the same way in Polish.
Well, Jellei(in a post above) somehow determined that "her" here is an objective personal pronoun acting as an indirect object and not a possessive determiner, so a singular can't be as it's missing a determiner(either indefinite or definite article). Since "fruit" is a countable noun, that leaves us with only plural as a possible interpretation.
TBH, I have no bloody idea how he did that, but since he studied English philology and I didn't, I accept his expertise on this matter and accept that it's something beyond my ken. ;)