1. PRONOUNS
Pronouns are words which stand in place of nouns. There are many different kinds of pronouns, used in different ways and for different purposes.
The noun (or pronoun) a pronoun stands in for is called the antecedent.
Sally met Billy and they ate dinner.
antecedent antecedent

2. NEVER use a pronoun before using the noun it replaces
NEVER use a pronoun before using the noun it replaces. For example, you would not want to open a paragraph this way:
He had just arrived home. He placed his keys next to his phone, and pressed the button to check his messages. As usual, there were plenty of messages for John.

3. Pronouns can show possession:
That is her car.
That car is hers.
The dog chases its tail.
That is not yours, it’s theirs.
Where a pronoun is showing possession, it is both a pronoun and an adjective.

4. Nominative pronouns: objective pronouns:
Used for the subject of used as the object of a sentence or the subject of a verb or of a some verb. preposition.
I me
You you
He him
She her
It it
We us
They them

5. Subject of a sentence:
We remember well our last visit there.
You and she ought to see that movie
together.
They and I had the same lottery numbers.
James and he arrived at the same
conclusion.

6. Object of a verb: His comments struck me as odd.
They found her asleep on the couch.
She gave him and me a lift home from school.
This will easily entertain them and me.

7. Object of a preposition:
The awards were given [to them].
They went [with us] to the party.
He saw no real value [in it].
We came in third [behind her and him].

8. Nominative pronouns: objective pronouns:
Used for the subject of used as the object of a sentence or the subject of a verb or of a some verb. preposition.
I me
You you
He him
She her
It it
We us
They them
* Who whom
(“Who” is not a nominative pronoun, but follows the same rules.)

9. Never “mix and match” with nominative and objective pronouns:
Her and I are late for work.
(“her” is objective and “I” is nominative, but they both being used as subjects)
The dog barked at him and I.
(“I” and “him” are both used as objects)

10. reflexive: reflect back on a noun
She treated herself to a fancy dinner after a long week at work.

11. intensive: for emphasis
The two friends bought a half-gallon of ice cream and ate it all themselves.

12. demonstrative: point out something
That was probably the hardest decision I have ever had to make.

13. interrogative: asks a question
Whom do you think is the better candidate, Billy or Sally?

14. relative: begin a dependent clause
The workers who took last Saturday off were inconsiderate, leaving only two others to work all day.