Grammar Tips & Articles »

modal auxiliary verb

This article is about modal auxiliary verb — enjoy your reading!

51 sec read
  Ed Good  —  Grammar Tips
Font size:

We have ten modal auxiliary verbs: can, could, may, might, must, ought to, shall, should, will, and would. We use them to express the mood of the verb, which, most often, is the indicative mood (expressing something as a fact). The modals enable us to express obligation, necessity, permission, or certain conditional actions, as in I might write the book.

Notice that these words lack principal parts. For example, there is no past participle or present participle for these modal verbs. The word can does have could to express a sense of the past, but none of these words have traditional principal parts (infinitive, past tense, past participle, present participle). For example, there's no such expression as “to must.” Also, none of the modals may act as main verbs.

Often writers will drop a main verb when it's clear what the modal refers to. You should, too. See how it works?

Other auxiliary verbs—to be, have, and do—do have meanings as main verbs.

See primary auxiliary verb.

Rate this article:

Have a discussion about this article with the community:



    Use the citation below to add this article to your bibliography:


    "modal auxiliary verb." STANDS4 LLC, 2023. Web. 30 Sep. 2023. <>.

    Free, no signup required:

    Add to Chrome

    Check your text and writing for style, spelling and grammar problems everywhere on the web!

    Free, no signup required:

    Add to Firefox

    Check your text and writing for style, spelling and grammar problems everywhere on the web!


    Free Writing Tool:

    Grammar Checker

    Improve your grammar, vocabulary, and writing -- and it's FREE!

    Improve your writing now:

    Download Grammar eBooks

    It’s now more important than ever to develop a powerful writing style. After all, most communication takes place in reports, emails, and instant messages.