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Auxiliary Verbs: Helping Verbs and Modals


Ever wonder what that connection is for on your stereo amp with the letters "AUX" under it?  Maybe you've found a port at the back of your flat screen TV that's labeled "Auxiliary"? Maybe you've heard of something like the Ladies Auxiliary Fire Brigade?  In all cases, the word "auxiliary" suggests a supportive role, whether it's an peripheral device or a supportive service.  The auxiliary aspect adds more function and character to the whole system.  This explains the role of the auxiliary verb as well.  In fact, auxiliary verbs are more commonly known as "helping verbs" and "modal verbs."

How Do Verbs Help?


Auxiliary verbs are used in conjunction with main verbs to express shades of time (i.e., verb tense) and mood:

can, could, do, have to, may, might, must, need, ought to, shall, should, used to, will, would

The combination of helping verbs with main verbs creates what are called "verb phrases" or verb strings. In the following paragraph, the verb strings are underlined and the helping or auxiliary verbs are in bold :

As of next August, I will have been studying chemistry for ten years. You may wonder, "Does he really enjoy chemistry?" I should be honest: I used to love learning about chemistry, but now I might just change careers. I did not enjoy how much time it used to take away from my social life. Now, I would like to know if I can find real chemistry between another person and me.

Observe how some verb strings are broken up. This is typical in certain conditions:

  1. the inverted word order of questions;
  2. negative statements in which the adverb "not" negates the verb, as in "did not enjoy" (something which could escape your notice if you only ever use contractions!);
  3. the use of adverbs to emphasize mood or shades of tense, as in "I might just change careers."

How Do Verbs Adjust Modes?

One type of helping verb is called a modal auxiliary (or, just "modal"). Another way of thinking about modes is as moods or methods—modalities.  These are used to add conditions or meaning to verbs and are always followed by the base verb form. The modal verbs include:

can, could, may, might, must, ought to, shall, should, will, and would.
She can write well.

In this example, the word "can" adds the meaning that she is capable of writing well.

Diagramming Auxiliary Verbs

When diagramming helping verbs, you should keep them together with the base verb, regardless if the verb string is broken up by other words:

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Auxiliary Verbs

Last Updated: 02/08/2015


Karl J Sherlock
Associate Professor, English
Phone: 619-644-7871

  • Grossmont
  • Cuyamaca
A Member of the Grossmont-Cuyamaca Community College District