their(is apossesion prounon of there) for instance
he-his (he has agood cell phone- did u see his mobile phone?)
she-her (she has new notebook - did u see her new notebook?)
they-their (they have their luggages- they prepared they luggages for travelling.)
here, there . we are using them when we refer to specific place, this place almost near.
here ( can u come here plz?)
there ( can u see them there?, yes i can)
they're
he is
they are (they're ) they are coming fom there.