The main verb is also called the lexical verb or the principal verb. This term refers to the important verb in the sentence, the one that typically shows the action or state of being of the subject. Main verbs can stand alone, or they can be used with a helping verb, also called an auxiliary verb.
Helping verbs do just what they sound like they do—they help! Different helping verbs help or support the main verb in different ways. For instance, they can show tense (which indicates when an action happened), ability, intention, or possibility. The primary helping verbs are to be, to do, and to have. To better understand how helping verbs support main verbs, consider the examples below:
I am driving to the beach. Here, the auxiliary verb “am” (a form of to be) lets the reader or listener know that the main verb in the sentence—in this case, “driving”—is happening continuously in the present. Different forms of to be could be used as a helping verb to explain when the driving is occurring (e.g., was driving, will drive, or had been driving).
To be used by plants, the N2 must be transformed through a process called nitrogen fixation. Fixation converts nitrogen in the atmosphere into forms that plants can absorb through their root systems.
