An adjectival phrase is commonly defined as a phrase that plays the role of an adjective, where a single word that describes a noun is changed into a longer phrase. The adjectival phrase, also called an adjective phrase, is a group of words that serves to describe something. There are a number of these kinds of phrases, but any phrase that is descriptive can properly be called an adjectival phrase.
One type of adjectival phrase is simply, as mentioned above, the creation of a longer phrase from a single adjective. For example, the adjective “big” can be changed to a comparative phrase like “bigger than me” and be called an adjectival phrase. An adjective like “small” can get added modifiers, i.e. “really, really small,” where again, the single word is made into a phrase that still includes an adjective.
Some adjectival phrases do not actually include adjectives. For example, changing an adjective like famous, educated, or civic minded to something like “a person of substance” takes all of the adjectives out of the phrase, but leaves something that can be called an adjectival phrase because it still describes the person. These phrases effectively illustrate the grammatical ways that a phrase can change, yet still provide the same description of a person or other noun.
Along with the above, there’s another type of phrase that plays the role of an adjective. This one sometimes has to be treated more carefully, because it contains compound elements that need specific punctuation. For example, take the phrase “bright-orange sun.” Here, if the writer did not use the hyphen, the phrase would be understood as a sun that has a brilliant light and is also orange in color. With the hyphen, the meaning changes to a sun that displays a vibrant bright-orange color and does not assess the intensity of the actual light.
In general, the adjective is a very important element of the English lexicon. The adjectival or adjective phrase compliments the adjective as a grammatical “sub-set” that is useful in more detailed analysis of the language. Descriptive elements such as adjectival or descriptive phrases play an important role in helping to enhance the communicative power of the English language, and many linguists find it worth looking at how adjectives or descriptors are used to provide information to listeners or readers.