The copula verb is a verb that connects a noun or subject directly to another word without the use of prepositions. In some books and other sources, this type of verb also been called a “copular” verb, because it connects. Some linguists and others find the phrase “copula verb” to be a bit more innocuous.
Examples of copula verbs include the verbs “be” and “look.” Other copula verb examples include verbs that correspond to the five senses, such as taste, smell or sound. Some other copula verbs have become relatively obsolete in use. One example is the word “prove.” While English speakers in past times may have used phrases like, “these efforts prove difficult,” modern English speakers are likely to use other alternatives to describe something that is hard to do.
Often, copula verbs link the subject of a sentence to an adjective. For example, the English speaker might say, “this smells good,” or alternately, “this is good.” Both of these are simple uses of the copula verb that include the positive general adjective “good.”
It’s important to note that some copula verbs also function as what’s called an auxiliary verb. The verb “be” is an example of this. The auxiliary verb, also called a helper verb, is a verb that complements another verb. For example, if an English speaker says “I am flying” the first person singular form of the verb “be” assists the primary verb “flying,” which describes the actual activity. As a copula verb, the word “be” could be used in a sentence like “this fruit is rotten.”
One challenge that beginners in the English language might have with copula verbs is the issue of subject and verb agreement. Speakers and writers need to be sure that the subject and the verb both use the right singular or plural forms. Non-native English speakers may feel the need to consult references to apply the right forms of copula verbs and their subjects.
While the copula verb often links to an adjective, some may link to adverbs. An example is the phrase “This smells horribly.” This phrase may be grammatically incorrect, but phrases like these are somewhat common usage in some English speaking communities. Another prime example is the use of “awfully” as an interjection in a copula verb phrase: if an English speaker says “This steak is awfully rare,” the linking of the adjective rare to the subject has been supplanted in a sense by the word “awfully,” which is acting as an adverb, modifying the adjective.