The complete verb of a sentence in English grammar consists of the main verb and the helping verbs that go with it. It could contain as many as four verbs, and words that function as adverbs or infinitives are not part of it.
To determine the complete verb of a sentence, one should first identify the main verb. The main verb tells what the subject of the sentence is doing. For example, in the sentence "Jane was working on an essay," the main verb is "working" because that is what Jane, the subject, was doing.
All helping verbs are identified after the main verb. Helping verbs take different forms of the verbs "have" or "be." In the sentence, "Jane was working on an essay," the word "was" functions as a helping verb. The complete verb in this sentence is "was working."
Adverbs, such as the word "not" and any words that form contractions using "not," are not part of the complete verb. For example, in the sentence "He didn't enjoy the movie," the word "not" is contracted with the word "did." The contraction "n't" would not included, so the complete verb in this sentence is "did enjoy."
Infinitives, which usually begin with the word "to," are not part of the complete verb either. In this sentence, "They were going to party all night long," the phrase "to party" functions as an infinitive. The complete verb in this sentence is "were going."
Complete verbs might stand alone when used with present and past tense verbs. In the sentence "I took the test," the past tense verb "took" acts as the main verb, and there are no helping verbs in the sentence. The same is true of the verb "take" in the sentence "I take a geometry class."
Present and past participles cannot stand alone and must be accompanied by a helping verb. The present participle form of "take" is "taking," and the past participle form is "taken." In the sentence "I will be taking piano lessons," the verb "taking" is accompanied by the helping verbs "will be."
In the sentence "I have taken dance classes," the verb "taken" is accompanied by the helping verb "have." The complete verb for this sentence is "have taken." An example of a sentence with one that has four words is "I will have been taken to the emergency room by then."