What Is a Modifier in Grammar?
A modifier is a word, phrase, or clause that acts as an adjective or adverb to provide further information about an additional word or word group (called the head). A modifier can also be called an adjunct.
Modifiers in English involve adjectives, adverbs, demonstratives, possessive determiners, prepositional phrases, degree modifiers, and intensifiers.
Modifiers before the head are called premodifiers, while modifiers after the head are called postmodifiers. Modifiers may be restrictive (essential to the meaning of a sentence) or nonrestrictive (additional but nonessential elements in a sentence).