Possessive pronouns show to who/what something belongs. As in English possessive pronouns change slightly in case. For example, In English we say. This house in mine. This is my house. It changes in case.
In English our pronouns are: my, your, his/her/its, their our,. However, in Polish again possessive pronouns agree in in case gender and number.
They answer the question – whose does it belong?.
Rozmawiałam z moim szefem o naszym projekciem.
I spoked with my boss about our project.
Dawno nie widziałem mojej siostry ani jej męża.
I didn’t see my sister or her husband for a long time.
Przedstawię cię mojemu przyjacielowi, polubisz go.
I will introduce you to my friend, you will like him.
Pójdę na spacer z moim psem.
I will walk with my dog.