Noun phrases can contain premodifiers before the noun, post-modifiers after the noun, or both. Premodifiers like "white" or "three old Democratic" directly modify the noun. Common post-modifiers are prepositional phrases like "on the table" or "in the store". A full noun phrase unites all the premodifiers, noun, and post-modifiers, such as "the boys on top of the house".

1. Structures of Noun phrases
Noun Premodifiers- Modifiers before the noun are called premodifiers. (modify means to
limit, restrict, characterize, or otherwise focus meaning). All of the premodifiers that are
present and the noun together form a noun phrase.
Noun Post-Modifiers -Modifiers coming after a noun are called post-modifiers.
1). NOUN PHRASE: premodifiers + noun
e.g.
a). White house
white is a premodifier and house is a noun.
b). The three old Democratic legislators
the three old Democratic is premodifier and legislators is a noun.
2). NOUN PHRASE -- noun + post-modifiers. (The most common post-modifier is
prepositional phrases).
e.g.
a). The glass on the table
on the table is the post-modifier
b). The boy in the store
in the store is the post-modifier.
3). NOUN PHRASE -- pre-modifier + noun + post-modifier.
The noun together with all pre and post-modifiers constitutes a single unit, a noun phrase
that indicates the complete reference.
e.g.
The boys on top of the house.
The is thepremodifier, boys is the noun,on top of the house is the post-modifier.