Her is a possessive pronoun and can be used both as a subject phrase and an object phrase. I can't be used alone as a subject. subject: Her dog ate my lunch. object: I kicked her dog. Then I kicked...
His is a possessive pronoun and can be used both as a subject phrase and an object phrase. It can't be used alone as a subject or object, his requires the noun that belongs to the word.subject: His...
"They" is a subject pronoun, since it is the opening word of the phrase. For example: They ate lunch. They played with me. If it was an object pronoun, it would read: I played with they. Since you...
You can be both a subject and an object pronoun. You have a nice car (subject). I will call you tomorrow (object). It and one can also be both subject and object.