The word or phrase using before a noun modifies it,is called a modifier.it give more information about a noun.it works like an adjective in a sentence. It is used before or after of the headword of a sentence.sometimes there may be modifier of an adverbial phrase.Determiners,adjectives and noun-adj. can be used as modifier.
Modifiers are of two kinds.1.premodifier and 2.post modifier
When any modifier is used before a noun or noun phrase,it is called premodifier.it is used before the headword of a noun phrase and after the determiner of it.There are different types of premodifier.
a.Adjective as premodifier:when an adj. is used before a noun or noun phrase.it is also called attributive use of article.i.e.a wise boy,an interesting story.
b.participle as premodifier:when a participle is used before a noun or noun phrase.only present(v-ing) and past participle(v-p.p) are used in this case.i.e. A sleeping dog,a learned man,running train,polluted air.
c.noun as premodifier:when a noun modifies another noun.i.e.train journey,bus fare,sea beach.