In a book(Wren and Martin updated Indian edition) I am reading it is said:
The forms my, our, your, her, their are called Possessive Adjectives because they are used with nouns and do the work of Adjectives; as,
This is my book.
Those are your books.
That is her book.
My understanding is that my, your and her can be replaced with adjectives in the above sentences as:
This is the red book.
These are better books.
That is a small book.
In the book I am reading, it further says mine, yours, hers are possessive pronouns, as used in following sense:
This book is mine.
These books are yours.
That book is hers.
That idea of yours is excellent.
But my question is that mine, yours, hers are infact taking the position of Predecative adjectives as:
This book is red
These books are better
This book is small
So, can mine, yours, hers be considered as Possessive adjectives? If not then why?
Best Answer
Possessive-adjectives are not adjectives. Possessive pronouns are certainly not adjectives
Possessive-adjectives can function in some ways like adjectives (my book, red book). But they are can't form comparatives or superlatives (*a more my book, *the myest book). And they can't form a predicate (*this book is my.)
The possessive pronouns act like nouns. In modern English, they seem usually to appear in the predicate "It's mine!". In older forms of English they were seen in the subject (consider the Lord's Prayer: "For thine is the kingdom" thine is the old singular form of yours). Modern English seems to prefer "my one" in this position: "My one is better than yours."
Nouns and pronouns can appear as predicates. "It's a cat." "I want him." and so on. In the sentence "It's mine" the word mine is acting as a pronoun, not as an adjective. The word "mine" can't function as an adjective *"mine book" is incorrect.
It is best not to think of words like "my" as replacing adjectives. But instead, think of them as forming their own special class of words, which go before nouns to indicate possession.