An adverbial modifier is a word or phrase that is used to modify another part of a sentence, typically a verb or adjective. When used properly, these modifiers provide additional information about an action or some part of a sentence and answer a question about it. In the sentence, “He crossed the bridge quickly,” the word “quickly” is an adverbial modifier. The modifier in this example answers the question, “How did he cross the bridge?”
In general, the purpose of an adverbial modifier is to provide additional information within a sentence and modify another part of it. These modifiers can be fairly simple, though in some sentences they can become quite a bit more complex. In its most basic form, an adverbial modifier can be a single word, which is typically an adverb. Such modifiers are often formed through the addition of the suffix “-ly” to the end of an adjective.
The word “loud” is an adjective that is used to describe a noun. It usually provides information about the sound that the word it modifies makes. “Loudly,” however, is an adverbial modifier that describes a verb or an adjective to provide information about how something was done.
An adverbial modifier can also be quite a bit more complex, since it can take the form of a phrase and still have the same function. In a sentence like “He walks his dog,” there is no adverbial modifier. There is a subject in the form of the pronoun “He,” a predicate consisting of the verb “walks,” and the direct object “his dog.” This direct object is a noun phrase that consists of a possessive pronoun, or possessive adjective, “his” and the noun “dog.”
The addition of an adverbial modifier to this sentence can be quite simple. “He quickly walks his dog,” expresses the same general point, but provides additional information. The adverb can be moved around within the sentence, so it is just as grammatically accurate as “He walks his dog quickly.” This is also true of longer adverbial phrases.
Addition of an adverbial phrase can certainly make this example more complex. For example, “He walks his dog at the same time every night,” is effectively the same sentence, but with quite a bit more information. In this example, the subject remains the same, “He,” and most of the predicate is intact, “walks his dog.” The adverbial phrase “at the same time every night,” has been added and provides an answer to the question “When does he walk his dog?”
Much like the one word adverb, this phrase can be moved around within the sentence. “At the same time every night, he walks his dog” conveys the same meaning and is just as grammatically accurate. In this example, the modifier consists of a prepositional phrase beginning with the preposition “at” and the noun phrase “the same time every night.” This phrase is made up of a determiner, “the,” an adjective phrase consisting of “same time every” and finally the noun it describes: “night.”