Your eyes are nouns. Your mouth is a noun. Your feet and teeth
and shoulders are nouns (and a noun). Your hair, more or less
a noun. Your ideas are nouns. As a person, you are a noun.
The place you find yourself is also a noun, every new place
you arrive at or leave, all nouns. The things you take with you
and leave behind. A grammar diagram is a noun: I, a subject noun,
love you, a direct object to a noun. You, also a subject noun,
love someone, another direct object to a noun. I give you words,
an indirect object (if there ever was one). The words are a gift,
a subject compliment. Sometimes, the words make you unhappy,
an object complement. These words, a binary code of zeros and ones,
are an appositive noun; flawed words, an adjective noun.
A sonnet is a noun. A feeling is a noun. A change of heart…

An unchangeable heart is an irrevocable noun, a final noun.

 

From The Writer’s Guide to Common Grammar