Possessive Adjectives vs Pronouns

English has two sets of possessive words: possessive adjectives and possessive pronouns. The adjectives are my, your, his, her, its, our, their — they always come before a noun: 'This is my book.' The pronouns are mine, yours, his, hers, ours, theirs — they stand alone without a noun after them: 'This book is mine.' The key difference is simple: if a noun follows, use the adjective form; if no noun follows, use the pronoun form.

A common mistake is mixing the two forms: 'This is mine book' is wrong because 'mine' is a pronoun and should not come before a noun. The correct sentence is 'This is my book' or 'This book is mine.' Notice that his is unique — it works as both an adjective ('his car') and a pronoun ('the car is his') without changing form. None of these possessive words use an apostrophe: never write 'your's,' 'her's,' or 'their's.' This distinction between adjective and pronoun forms is tested in Cambridge A2 Key and B1 Preliminary writing sections.