Here's why:
* Transitive verbs require a direct object (the receiver of the action).
* Intransitive verbs do not take a direct object.
Helping verbs, like "be," "have," "do," and "will," modify the main verb in a sentence and don't express an action themselves. They assist the main verb in conveying tense, mood, or voice.
Example:
* "I have written a letter." ("written" is the main verb, "have" is the helping verb.)
* "She will be here soon." ("be" is the main verb, "will" is the helping verb.)
In these examples, the helping verbs don't perform an action or have a direct object. They simply help the main verbs express the intended meaning.
Therefore, helping verbs are not classified as transitive or intransitive.