A possessive pronoun is a specific type of word that functions much like any other pronoun but indicates possession. Pronouns, in general, are words used to replace a noun within a sentence, such as “it” or “him.” When the noun phrase being replaced includes a possessive adjective, such as “my book,” then a possessive pronoun is used to indicate that the replaced phrase was also possessive. Common examples in English include words like “mine,” “his,” and “hers;” all lack the use of apostrophes that commonly indicate that a noun is possessive.
The purpose of a possessive pronoun is to allow a single word to replace another noun phrase in a sentence, to avoid repetition and to make communication easier. For example, it would be grammatically accurate for someone to write, “That is my book, this is your book, please stop using my book,” but it is repetitious and somewhat unwieldy. In order to simplify this type of sentence, a possessive pronoun can be used in place of any of the noun phrases that include a possessive adjective.
A noun phrase is simply one or more words that create a single phrase together that functions as a noun within a sentence. Simple sentences like “Tom runs fast,” have “Tom” as a noun phrase that acts as the subject of the sentence. A more complex sentence like “The dog is happy,” has “The dog” as the subject and a noun phrase made up of an article, “The,” and a noun, “dog.” Noun phrases can also include possessive adjectives, such as “my” to indicate who or what possesses something.
In the previous example, “That is my book, this is your book, please stop using my book,” the noun phrase “my book” includes a possessive adjective and a noun. This can be replaced by a possessive pronoun such as “mine,” while “your book” can be replaced by the possessive pronoun “yours.” The entire sentence might be reworded through the use of such pronouns to flow better as “That is my book, this is yours, please stop using mine.”
Other common forms of possessive pronoun include third person ones such as “hers” and “his” and the plural forms “ours,” “yours,” and “theirs.” These words retain the same form regardless of whether they are used as the subject of a sentence, or as an object within it. A possessive pronoun also does not require an apostrophe, unlike a noun such as “dog” that changes to “dog’s” to indicate possession.