“–nya” is used as the counterpart of the English possessive pronoun “its”, i.e. it refers to something inanimate or non-human. It makes no distinction between male and female. If you really need to know the gender of the persons concerned, you can usually infer it from the wider context of the text or conversation.
Important Notes:
If -Nya can be used for inanimate things or non-human living things, dia and mereka usually cannot. Dia and mereka are used only to refer to people. So you cannot usually say, for example:
| Bapak Warouw punya mobil baru. *Dia Toyota. | Mr Warouw has a new car. It’s a Toyota. |
| Kediri dan Mojokerto itu kota besar.*Mereka di Sungai Brantas. | Kediri and Mojokerto are big cities. They are on the Brantas River. |
[The asterisk * indicates an ungrammatical sentence.]
