• Subject of a verb in an independent clause (Subject of a sentence)
  Example: He was elected president of the class.

• Subject of a verb in a dependent clause
  Example: While she was shopping, Layla lost her sunglasses.

• Subject complement after forms of the verb "to be."
  Example: The recipient of the award was he.

  (In conversation, this rule is often ignored; however, it should be observed in writing. If a sentence sounds awkward because of the sentence complement, reword the sentence by moving the pronoun into the subject position.

  Example: He was the recipient of the award. )

• After "than" or "as" when a verb is implied after the pronoun
  Example: Maurice is stronger than I.

Use the objective case when it is used as one of the following:

• Direct Object
  Example: The police officer arrested them.

• Indirect Object
  Example: Mary bought him a sweater.

• Object of a Preposition
  Example: Jaime walked away from her.

• Object of a Verbal
  Example: Convincing them to donate was the committee's goal.

Possessive Case

Use the possessive case to show ownership. Remember, an apostrophe is used with a pronoun only as a contraction, NEVER to show possession.

Examples:
Do you know his address?
They took their car in for repair.
Is this your book?