The term “case” applies to nouns and pronouns.
What “case” a noun or pronoun is in depends upon how the noun or pronoun is used in a sentence.
The only cases still in use in English are:
Nominative (nouns/pronouns used as the subject of a verb)
The fireman climbed the ladder. (“fireman” is the subject of the verb “climbed.”)
He rescued a child. (“He” is the subject of the verb “rescued.”)
Accusative (nouns/pronouns used as the object of a verb or a preposition)
The fireman rescued the child. (“child” is the object of rescued. “child” receives the action of the verb.)
The story is in the paper. (“paper” is the object of the preposition “in.”)
Possessive (nouns/pronouns used to show possession)
The child’s mother kissed the fireman in gratitude. (“child’s” is the possessive of child. It shows that the noun following it, “mother,” belongs to the child.)
The only case that changes a noun’s spelling is the possessive case.
English nouns form the possessive by adding an apostrophe.
Mary’s hat (Mary’s is the possessive form of Mary.)
The children’s toys (children’s is the possessive form of children)
The boys’ bicycles (boys’ is the possessive form of boys)
St. James’s Park (James’s is the possessive form of James.)
NOTE: Case is more complicated when it comes to pronouns. For that reason, many of the most common English errors have to do with the use of pronouns.
To use pronouns correctly, you must learn their subject, object and possessive forms.
You must also understand the grammatical concept of subject and object.
Subject pronoun forms:
I, you, he, she, it, we, they, who
Object pronoun forms
me, you, him, her, it, us, them, whom
Possessive pronoun forms
1. forms used in front of nouns to show possession:
my, your, his, her, its, our, their, whose
2. forms used alone to indicate possession:
mine, yours, his, hers, its, ours, theirs, whose
