Verbs express the action performed by the subject or the subject's state of being. Sentences can contain more than one verb, or a verb phrase. Verb phrases contain a main verb, or the main action of a sentence, which is always an action verb that expresses mental or physical action or a linking verb that expresses a state of being, and one or more helping verbs, which help the main verb and cannot exist without it. However, action and linking verbs are infinitive phrases, not main verbs, when they follow the word "to."
Determine whether the sentence contains one verb or multiple verbs by identifying the action the subject is performing or the subject's state of being. For example, the sentence "John tied his shoes" contains only the verb "tied," so there is no need to identify the main verb. However, the sentence "John was tying his shoe" contains the verb phrase "was tying," and the sentence "John learned to tie his shoe" contains the verbs "learned" and "tie" but not a verb phrase. The main verb needs to be identified in both of these sentences.
Identify the main verb in a verb phrase by determining the subject's main action or state of being. For example, in the verb phrase "was tying," the main action the subject is performing is tying while the verb "was" merely helps the action verb "tying" by expressing that this action happened in the past. Thus, "tying" is the main verb and "was" is a helping verb.
Identify the main verb in a sentence containing multiple verbs but no verb phrase by asking yourself which verb is expressing the subject's action or state of being. For example, in the sentence "John learned to tie his shoes," both "learned" and "tie" are action verbs. However, "tie" follows the word "to," so "tie" is part of an infinitive phrase and does not express the main action of the sentence. "Learned" is the main verb because John performed the action of learning, and tying his shoe is what he learned, not the action he performed.