[Grammar] identify the adjective

[Phaedrus]

Can we think of a case where my, your, their, his, etc., co-occur with articles and/or demonstrative determiners in the same noun phrase? (We can speak of "the cat," "that cat," "his cat," but can we speak of "the his cat," "his that cat," "his a cat," etc.?) If not, perhaps that's because my, your, their, his, etc., function exactly the same way as articles and demonstrative determiners. They can introduce adjective modifiers of nouns, but they cannot introduce themselves as adjective modifiers of nouns, because they aren't adjectives -- they're determiners.