उसकी vs. उसका
In many of the duolingo lessons(beta) for Hindi there is a redundant mistake. This mistake is that sometimes उसका( a masculine Hindi pronoun for the English his ) replaces उसकी ( a feminine Hindi pronoun for the English her) in duolingo. I ask that the developers or any others who are working on creating duolingo for Hindi to fix this error to prevent further confusion as the definitions of the two words are not the same.
Actually, whether it is उसका or उसकी depends on the gender of the thing that is possessed, not on the gender of the possessor. Therefore, they are not Hindi equivalents of his and her. For example:
उसका सेब - his/her apple (सेब is masculine)
उसकी किताब - his/her book (किताब is feminine)
Right. It's not a mistake. Another illustration. It'll be उसकी बहन(his/her sister) regardless of the person whose sister we're talking about. That's because उसकी here is modified by बहन and the one whose बहन we're talking about doesn't make any difference. It's similar to how French works in this regard.