बेटे could be translated as "children", correct? If someone had two children one son and one daughter, one would still say बेटे meaning the children collectively, right?
उसका masc sing उसके masc plural /masc sing oblique/masc plural oblique उसकी feminine sing/plural/oblique
if something is oblique, then how do you know which one to use (since you don't know if its feminine or masculine)?
It is either his or her as they are the same word, but not their. Their son would be उनके बेटे