A coordinate adjective can be a somewhat difficult grammatical concept to grasp. A series of adjectives might be considered coordinate when they work together to characterize another word or words, most often a noun. Each coordinate adjective will share an equal effect on the noun it is modifying. When written out in a sentence, commas generally should be used as a separation between each of the adjectives.
Adjectives are words that are used to describe other words. For the most part, adjectives can help describe what kind something is, how many there are or which one something is. Sometimes it takes more than one adjective to adequately identify a noun. This is when coordinate adjectives come into play. An adjective is considered to be a coordinate adjective when put in succession with other adjectives and used to describe the same noun.
Usually, a coordinate adjective is identified by the comma or commas that separate the series of adjectives before a noun in a written sentence. For example, in the sentence "Max is a happy, healthy puppy," the words “happy” and “healthy” are coordinate adjectives. They help describe the noun “puppy.”
A series of adjectives are not always coordinate, however. There are two tests used to determine whether adjectives are coordinate. First, the comma is removed from between the adjectives and replaced by the word “and,” and if the sentence still makes sense, then the adjectives are considered coordinate. For example, the sentence "Max is a happy and healthy puppy" is grammatically correct and sounds logical when spoken. Therefore, the adjectives “happy” and “healthy” are coordinate adjectives in this sentence.
If the sentence no longer makes sense after replacing the comma with “and,” then the adjectives are not considered coordinate adjectives. An example of non-coordinate adjectives is found in the sentence "We have two pudgy bulldogs." The words “two” and “pudgy” are the adjectives. Trying the first test, the sentence becomes "We have two and pudgy bulldogs." When the word “and” is placed between the adjectives, the sentence is no longer grammatically or verbally correct.
The second method used to test whether adjectives are coordinate is switching the order of the adjectives in the sentence. If the sentence is still correct and makes sense, then they are coordinate adjectives. In the sentence "Max is a healthy, happy puppy," switching “happy” and “healthy” does not affect the sound or correctness of the sentence.
When a sentence passes both of these tests, the adjectives in the sentence are considered to be coordinate adjectives. Using the non-coordinate example, to try the second test, the sentence becomes "We have pudgy two bulldogs." Reversing the order of the adjectives in this sentence makes it completely illogical.
Checking for comma usage and testing the sentence using these two methods can help determine whether adjectives are coordinate adjectives. When writing, it is important for one to remember not to insert a comma between the final adjective and the noun. Putting a comma there would turn the phrase into more of a list than a description.