what is modifier

In linguistics, a modifier is an optional element in phrase structure or clause structure that modifies the meaning of another element in the structure. Modifiers can be adjectives, adverbs, phrases, or clauses that give extra information about a noun or verb in a sentence. For example, in the sentence "I rode the earliest train into the city," the word "earliest" is a modifier that provides extra information about the train. Modifiers can be placed before or after the word they modify, depending on the type of modifier and the rules of syntax for the language in question. In addition to their use in language, modifiers are also used in medical billing to indicate that a service or procedure performed has been altered by some specific circumstance, but not changed in its definition or code.