What type of verbs are referred to as auxiliary verbs?

Auxiliary verbs, often known as helping verbs, play a pivotal role in English grammar as they assist main verbs in forming various tenses, voices, and moods. This function allows for more complex verb structures, enabling speakers and writers to convey time frames (like past or future), as well as conditions such as passive voice or progressive aspects. For example, in the phrase "She is running," "is" serves as the auxiliary verb, helping to indicate the ongoing action of running.

The other options do not encapsulate the primary function of auxiliary verbs. The first option suggests that these verbs only describe actions, which does not account for their role in forming different tenses and aspects. The third option refers to verbs that define states, which typically describe conditions or situations but do not assist in the action's grammatical structure. The fourth option lists main verbs in a sentence, which represent the primary action or state, distinct from auxiliary verbs that support these actions. Understanding auxiliary verbs enhances comprehension of verb conjugation and the overall structure of the English language.