On the British Council’s Learn English website, an “adjective phrase” is described simply: “See adjective”. In truth, adjective phrases are more complicated than that, but there’s a grain of helpful truth here. Adjective phrases are more complex forms of adjectives and serve the same purpose: to describe a noun in a sentence.
Put simply, adjectives are describing words. Adjectives can be colors, sizes, shapes and emotion. These words add description to sentences to help convey deeper meaning. Consider the sentence “There was a boy outside.” You know the boy was outside, but adding adjectives gives the sentence substance. The sentence "There was a tall boy outside," for instance, gives you a bit of an idea of what the boy looked like.
Adjectives usually go before the noun (person, place or thing) that they describe. In the above sentence, “tall” describes the boy, so it goes before the noun “boy.” Additionally, adjectives can be used after a noun with a “link verb,” like “be,” “look” or “feel.” You could say “The boy is tall” or “The girl looked sick.” Adjectives still describe the noun, even if they come after the noun.
Whereas adjectives use one word to describe a noun, adjective phrases use several words to add a more complex description of a noun. In their simplest form, adjective phrases are a combination of adjectives. “There was a tall, red-headed, hungry-looking boy outside” provides considerably more information about the boy than simply saying he’s tall. “Tall, red-headed, hungry looking” is an adjective phrase.
Complex Adjective Phrases
Adjective phrases can be more than a string of adjectives. Consider the sentence “My friend Sally is really fond of sandwiches.” In this sentence, the adjective phrase “really fond of sandwiches” describes Sally’s personality. Adjective phrases can be used to complement the subject or object of a sentence too, such as in the sentence “You look tired but happy today.” “Tired” and “happy” both describe the subject of the sentence (“you”).
Adjectives are often used in writing and speaking in the form of an “appositive,” a phrase supporting a noun or phrase by describing it. “The boy, red-headed, tall and hungry, was outside of my house” uses an adjective phrase as an appositive. The simple sentence is “The boy was outside my house,” but all of the adjectives -- red-headed, tall and hungry -- sit in the appositive to describe him.