Grammar girl here.

Every once in a while I get questions about word pairs, such as wooden wooden or wool

and woolen.

Sometimes it's a cranky commenter insisting that you can't wear a wool sweater, that

you can only wear a woolen sweater.

And sometimes it's just someone wondering whether he should write about a wood bench or

a wooden bench.

One reason for the confusion is that although we have adjectives in English, we can also

use nouns as adjectives.

When we do so, they're called attributive nouns.

Some nouns often act like adjectives, some only do it sometimes, and others rarely are

never act like adjectives.

To make matters even more confusing, some words are both nouns and full adjectives.

To think about attributive nouns, let's consider this sentence, which has three nouns acting

like adjectives.

Ask me in a cotton dress to eat avocado sandwiches and dance on a wood floor, and I'll be happy.

In cotton dress, cotton is an attributive noun that's acting like an adjective, telling

us what kind of dress I want.

Avocado is telling us what kind of sandwich I want, and wood is telling us what kind

of floor I want to dance on.

We could substitute a word that's only an adjective in place of all those nouns.

I could write something like dress me in a loose dress to eat hot sandwiches and dance

...