-’s

suffix
1
belonging to
یِ, -ِ
2
used to refer to somebody’s home or, in British English, a particular shop
خانهٔ کسی, مکان کسی, خانه, منزل, فروشگاه, مغازه, دکان
Shall we go to David's tonight?
(British English)I’ll call in at the chemist’s on my way home.
short form
1
used after he, she or it and where, what, who or how to mean ‘is’ or ‘has’
است
2
us
ما, ماها
Let's go out for lunch.