When to use उसकी (uski) or अपनी (apni)
I understand that these are possessive pronouns, but what is the rule for using them?
I believe it depends on the gender of the object being possessed.
So for example, for book, apni is used because it's feminine
but for dress, uski is used.
Does this mean dress is masculine? That just seems strange!

Question

When to use उसकी (uski) or अपनी (apni)
I understand that these are possessive pronouns, but what is the rule for using them?
I believe it depends on the gender of the object being possessed.
So for example, for book, apni is used because it's feminine
but for dress, uski is used.
Does this mean dress is masculine?  That just seems strange!

Answer

उसका / उसकी means "that one's own", in other words, "his/her/its". अपना / अपनी is often translated as "one's own" - that's not quite what it means, but it is an easy way to remember it. I believe it really means "my/your/his/her/its own", and is used to indicate when something belongs to a person just referred to, like when we say "my OWN room", मेरा अपना कमरा. The endings in the simple singular case are typically आ for masculine (or ए in certain other cases) and ई for feminine. When no gender is specified, masculine is default.
Hopefully if this isn't right, it will be corrected, or maybe someone will give better examples.