Case refers to changes in the form of a noun or pronoun depending on its function in a sentence. In English, only personal pronouns inflect for case, and they only have three case-marked forms:
- Subject: I went to the store.
- Object: She looked at me.
- Possessive: They took my book.
More formally, subject, object, and possessive can be called nominative, accusative, and genitive. The use of accusative for the object case is somewhat misleading, as the English object case covers both the accusative ("direct object") and dative ("indirect object") functions of the pronoun.