Arabic/1stPersonSingPoss

ـِي

Adding the suffix ـِي (ee) to a word to say it's yours.

an example:

كتاب --> كتابي

kitaabun-->kitaabee ki-taa-bun -->  ki-taa-bee a book-->my book

It does not matter if it was: kitaabun or kitaabin or kitaaban meaning "a book". All become kitaabee. kitaabun-->kitaabee kitaaban-->kitaabee kitaabin-->kitaabee

This makes it much simpler grammatically to say something is yours than to say something is his, or hers.