Hello Bodi,
Here are som examples:
- Benimki kalem = The pen which I have
- Seninki kalem = The pen which you have
- Benimki = The thing that I have / mine
- Seninki = The thing that you have / yours
- Benim kalemim yok, seninki alabilir miyim? = I don't have a pen, can I take (yours/the one that you have)?
- Senin kalemin yok! benimki alabilirsin. = you don't have a pen, you can take (mine/the one that I have).