ref – https://www.grammar-monster.com/glossary/noun_phrases.htm

What Is a Noun Phrase?

A noun phrase is a group of two or more words headed by a noun that includes modifiers.

note:
adjectives and adverbs are modifiers
Phrases can also be modifiers

the dog
the = modifier

a cat
a = modifier

a group of them
‘a’ and ‘of them’ = modifiers

The best car safety device
‘The best car safety’ = modifier

the man with her

‘the’ and ‘with her’ = modifiers

Examples of Noun Phrases

*highlighted is the head noun

People: the soldier, my cousin, dopey Alan, the lawyer with the big nose

Animals: that aardvark, one rat, a shark, funny Mickey

Places: the house in the corner, inner London, dirty factory, no shelter

Things: this table, our London Bridge, the sharp chisel, that nitrogen, last month, an inch, her cooking

Ideas: utter confusion, some kindness, your faith, the Theory of Relativity, a joy

Like any noun,

a noun phrase can function as a subject, an object, or a complement

within a sentence.

In each example below, the noun phrase is in bold and the head noun is highlighted.

Singing in the bath relaxes me.
Here, the noun phrase is the subject of the verb “relaxes.”

I know the back streets.

Here, the noun phrase is the direct object of the verb “know.”

She was the devil in disguise.
Here, the noun phrase is a subject complement following the linking verb “was.”

This man has a nice smile,
but
he’s got iron teeth.

“This man” is the subject of the verb “has.”

The phrase “a nice smile” is the direct object of “has.”

The noun phrase “iron teeth” is the direct object of the verb “got.”

I (subj) never learned (verb) from (preposition) a man who agreed with me.

The noun phrase “a man who agreed with me” is the object of the preposition “from.”

Here’s the “pronoun test”: I never learned from him.

him – a man

Every man of courage is (linking verb) a man of his word.

“Every man of courage” is the subject of the verb “is.”
The noun phrase “a man of his word” is a subject complement following the linking verb “is.”

Here’s the “pronoun test”: He is one.
He – Every man
one – a man