MAKING THE PRONOUN AND ITS ANTECEDENT AGREE:

ANTECEDENT = a noun to which a pronoun refers

• The car that I want is on sale.
  (car = antecedent    that = relative pronoun)
  
  
• The man on the boat thinks he is safe without a life jacket.
  (man = antecedent    he= personal pronoun)
  
  
• Does anyone have his or her book.
  (anyone = antecedent    his/her= possessive pronoun)
  
  

WHO and WHOM: Refer to persons and members of a group who take on "human qualities"

• Please give the book to the student who has her hand raised.
• The police officers who stopped my car were polite.

WHOSE: Refers to persons, animals and sometimes to things.

• The student whose books were lost is mad.

WHICH: refers to things, animals and persons considered as a group.

• The UO basketball team, which played tonight, is undefeated.

THAT: May refer to inanimate objects, places, things, ideas and animals.

• The theory that the earth is round is accepted as fact.

TWO or more antecedent are joined by a conjunction take a plural pronoun.

• Jody and Jerry coached their (her and his) basketball players.

Singular antecedents joined by OR / NOR take a singular pronoun.

• Neither Tom nor Jerry will present his case to Judge Ito.

With one singular and one plural antecedent joined by OR / NOR the pronoun agrees with the nearest antecedent.

• Either you or your pals must leave their car keys.
• Either your pals or you must leave your car keys.

Singular indefinite pronouns take a singular pronoun.

• Could someone please give me her book? (to a group of all women))
• Could someone please give me his book? (to a group of all men))
• Could someone please give me his or her book? (to a group of men and women))
• Anyone with a family history of heart disease should have his or her cholesterol checked.