Would "this is his chalk" also be correct?
Or, "This chalk belongs to him."
Technically that would be 'ini kapur dia', but I think it should be accepted. It's splitting hairs otherwise.
A year later, and "this is his chalk" is still marked as wrong!
because it is wrong. they gave similar meaning but grammatically it is not precisely the same. a year later, and you still dont know why it is wrong!
Thanks for your incisive contribution ... you do realise you're responding to a comment that's well over a year old, right?
It would be, but not for duolingo.