A pronoun is a word that substitutes for a noun:

Singular:	Professor Smith finished her grades.
Plural:	The Mechanics started their cars.

Do not use plural pronouns to refer to singular antecedents:

At the game everyone cheers at his or her (not their) skill level.

Treat collective nouns as singular unless the meaning is clearly plural:

Unit:	The audience cheers its baseball team.
Individual:	The crowd received their free baseball cards at the game.

Treat most compound antecedents connected by and as plural:

Jack and Jill went up the hill to fetch their pail of water.

When words like nor, or, either... or, or neither... nor connect compound antecendents, make the pronoun agree with the antecendent nearest to it:

Singular:	Either Jane or Diane should receive first prize for her sculpture.
Plural:	Neither the cat nor the dogs could eat their food.

Avoid ambiguous or remote pronoun agreement:

Ambiguous:	When George set the pint glass on the ceramic table, it broke.
Clear:	The pint glass broke when Grorge set it on the ceramic table
Remote:	This time the court ordered Derek to pay off his parking tickets. He had twenty, from speeding to running red lights, and he hadn't paid them for over a year. By the time Derek (NOT He) paid his tickets, he was in jail. (The pronoun He is too far from its antecedent Derek)

Avoid broad reference to this, that, which, and it:

He realized after the gunman entered his bedroom that he was not going to survive. He learned to accept this his death by hanging up the phone.

Do not use a pronoun to refer to an antecedent that may be implied:

After tattooing Mile's skin, Mr. Big colored it the tatoo with red and blue.

Modifiers which act as possessives cannot serve an antecedent:

In Shakespeare's Romeo and Juliet, Shakespeare (NOT HE) tells the story of teenage love.

Avoid the indefinite use of they, it, and you:

After someone crashes a car, the cops usually give advice. For example, after Mike crashed his car, the cops (NOT THEY) told him to slow down.

To refer to persons, use who, whom, or whose; to refer to inanimate objects or things, use that or which:

When she heard about my two children, one of whom (NOT WHICH) is an infant, she said, "How cute".

People wondered how a seventy-year old burglar who (NOT THAT) was blind could steal a television.

Avoid the whose/who's confusion: Who's is a contraction of who is; whose is a pssessive pronoun.

Pronoun Case:
Personal:	Subjective:	Objective:
Singular:	I	Me
	You	You
	He/She/It	Him/Her/It
Plural:	We	Us
	You	You
	They	Them
Relative:	Who	Whom

Use subjective pronouns in the subject or subject complement position:

Subject:	I left the circus because the ringmaster and I had quarreled.
	The blue ribbon goes to the racer who crosses the finish line first.
Compliment:	Ted confessed that the culprit was he.
	The Principal knows who you are.

Use objective pronouns as objects of sentences and prepositions:

Sentence:	My baby sister refused to listen to Dad or me.
Preposition:	Frank went on vacation with my sister and me.
	Ask not for whom the bell tolls.