They are not nouns. 

definition- pronouns take the place of nouns.

Jessica and Chris went to the movies because she likes him. They sat in the back because he didn't want to really see it; he wanted to see she instead. 

1st person- the person speaking (I)

2nd person- the person spoken to (you)

3rd person- th person or thing spoken about (he,she)

                              Singular vs Plural Pronouns

1st person- I, me, my, mine         we, our, ours,us

2nd person- you, yours, your        same

3rd person- he, she, it, its            they, them, 

                 his, hers, her,            their, theirs

                 him

Demostrative Pronouns

Very specific pronouns. Demostrative is a specific

Singular: this that        person, place, or thing. 

Plural: those these (ex) Those boys are wise guys. 

Always starts a question

     -who,whose,whom,which, what

                        usally used in a prepositional phrase. 

 An interragative sentence always ends with a question mark. 

Subject

(also called a nomative case)

Always the subject of a sentence. 

Singular:1st person i, 2nd person you, 3rd person he, she, it, and who

Plural: 1st person we, 2nd person you(as a group) 3rd person they, who. 

Object

(also called objective case)

-often the direct object

-often in prep. phrase

Singular and Plural: 1st me and us, 2nd You and same ( as a group), 3rd him,her, it, whom and them and whom