What role do helping verbs play in a sentence?

Helping verbs, also known as auxiliary verbs, play a crucial role in constructing verb phrases. They are used alongside main verbs to clarify the tense, mood, or voice of the action being described. For instance, in the phrase "is running," "is" is a helping verb that indicates the present continuous tense, showing that the action is currently occurring. By working together with the main verb, helping verbs help to form questions, negatives, and various verb tenses, thus providing clear context about when an action takes place and the manner in which it occurs. This highlights their essential function in providing grammatical structure to a sentence.