Is "my" a pronoun, an adjective, both or what?

[Hans Suhrweier]

I'm confused. In the sentence below, I know that the word "my" is a pronoun, referring to "Sarah." It is describing or providing additional information about "hair" and is therefore serving as an adjective. Is it a pronoun serving the function of an adjective or what? Is it a pronoun and an adjective at the same time? Can it be both? Which or what is "my"?

Sarah looked at herself in the mirror. "I need to comb my hair," she thought.

 

[Barb_D]

Welcome to Using English.

It's a possessive adjective.
Some people call them determiners.

 

[birdeen's call]

In English, possessive pronouns and possessive adjectives are different words. The first-person singular possessive pronoun is "mine". The first-person singular possessive adjective is "my". "My" is not strictly a pronoun, because it can't be used instead of a noun or a nominal phrase. We can't say

This car is dead. We'll have to take my.

We have to use "mine" or "my car". "My car" is the nominal phrase "mine" substitutes for.

"My" is sometimes called a pronoun by those who consider it an inflected form of "I", which definitely is a pronoun. Their view is that inflection can't change parts of speech.

The "mine" in

We'll have to take mine.

is definitely a pronoun. I'm personally less sure about the "mine" in

This car is mine.

Others may disagree, but I think this "mine" works like an adjective, like "blue" in

This car is blue.

I think so because I don't see what nominal phrase "mine" could substitute for here. The sentence

This car is my car.

isn't good at all.

 

[5jj]

This is one of those cases where labelling causes more problems than it solves. There are moderately sound arguments for using the '(possessive) adjective' label, and also for using the 'pronoun' label . Neither is necessarily correct or incorrect. Personally, I use 'determiner' and 'possessive', as seems appropriate at the time, for my, your, etc, and 'possessive pronoun' for mine, yours, etc.