rock as a adjective

[notmyname216]

I did not find the word "rock" listed in any dictionary as a adjective. Isn't "rock" a adjective in this sentence:

The rock wall crumbled and fell from old age.

[Casiopea]

'rock' is a noun in form, and when it's used to modify another noun like rock wall, it function as an adjective, which in this case makes 'rock' a substantive (a substitute).

[1] The wall, the one made of rock (noun), crumbled and fell from old age.
[2] The rock (adjective) wall crumbled and fell form old age.

Note, every word has a form -what it looks like - and a function - what it does.

[trustM]

I did not find the word "rock" listed in any dictionary as a adjective. Isn't "rock" a adjective in this sentence:

The rock wall crumbled and fell from old age.

Pay attention to your indefinite article: a adjective. You should have written AN adjective.

[notmyname216]

Thanks for the correction trustM.

Thanks for the explaination Casiopea.

[Casiopea]

You're welcome, 216.