Modal Verbs and Their Expressive Forms

As intermediate and advanced level speakers, deeper expression is one of the key elements that ranks you in that level of comprehension. To create sentences with more depth, sometimes your verbs require a little help. That’s where modal verbs fit into English grammar. You may have a basic understanding of these verbs, so in this article, we’ll review and go deeper into their function and usage.

What are Modal Verbs?

Modal verbs are auxiliary verbs that give sentences deeper and more well-rounded meanings.

Modal verbs include words like: can, may, must, should, would, could, might, will, and shall.

Their purpose is to provide additional information that enhances or helps another verb. In fact, they change the meaning of a sentence. Look at the sentences below to see what we mean.

  • Joe plays tonight.

The sentence states that Joe is playing tonight.

  • Joe can play tonight.

However, if you add the modal verb can to the sentence, it implies only that Joe has the ability to play tonight. Whether he will or will not play is not answered.

Can changes the function of the verb play, and that’s actually the function of a modal verb. We’ll explore the various expressive functions of modal verbs in the next section.

First, let’s review how modal verbs behave differently from normal verbs.

3 Key Differences Between Regular and Modal Verbs

1. Modal verbs never change form and have no infinitive or participle. Do not add -s, -ing, or -ed to a modal verb.

  • He can sense their fear.
  • She should play tonight.
  • They may have played yesterday.

2. Add “not” to make a modal verb negative in any tense.

  • He can not sense their fear.
  • She should not play tonight.
  • They may not have played yesterday.

3. Modal verbs are an auxiliary verb and therefore do not require an additional auxiliary in the negative or question form.

  • Should I go? – Correct
  • Do should I go? – Incorrect
    • He wouldn’t go. – Correct
    • He doesn’t would go. Incorrect

Expressive Forms of Modals

The function of a modal verb is to change the expression of a verb. This comes in many variations in English, so let’s break down some of those variations.


  • She can go when she’s done with her chores.
  • You may leave whenever you want.
  • Jessie can’t stay here tonight.
  • Can I go to the movies?
  • They won’t be able to make it this evening.

*Be able to is a modal phrase used to express both permission or ability (more on this below).*


  • I can speak English very well.
  • He could do backflips when he was younger.
  • Can you lift this bag for me?
  • Tom can’t run a mile.
  • She wasn’t able to see anything.


  • You can not smoke on an airplane.
  • He must not board the plane.
  • Why can’t she come with us?


  • You must stay home when you are sick.
  • I must go because I have an appointment in 20 minutes.
  • They should be here before we arrive every morning.


  • That must be him. He’s the only one wearing a yellow coat.
  • I haven’t seen him in years. He must be over 70 years old by now.
  • You must have said the right thing because he was very calm when I arrived.
  • That must have been the right place. It had the same porch swing I remember.


  • You should stop making such a big deal out of it.
  • You ought to change your plans.
  • You had better go apologize if you want your job back.

*Had better and ought to are more examples of modal phrases.*


  • May I sit here?
  • Would you take this to the garage for me?
  • Will you make me a sandwich?

*Though not technically correct, in casual speech you will also hear could and can used in a request.

  • Hey, could you come here for a second?
  • Can you take me to soccer practice tomorrow?


  • We could go to the park tomorrow.
  • You can ask, but I doubt she would say yes.
  • I may arrive a little late this evening.
  • You can catch the next train in 10 minutes.
  • Jerry said he might run in the Boston Marathon next year.

Lack of Necessity

  • You don’t have to go if you don’t want to go.
  • She need not worry about it. I have everything under control.

If- Sentences

  • If I were you, I wouldn’t say anything else about it.
  • If we’re going to the mall, we should bring some money.
  • If they’re thinking about running, tell them they ought to think twice about it.

That’s ten common variations of modal verb usage. Can you think of any more? Leave a comment below if anything comes to mind.

Modal verbs are used in a variety of ways and in different tenses. Be sure to practice using them in different situations and try some online exercises to reinforce what you’ve learned.

As always, visit the Magoosh Speaking Blog for all things ESL and grammar-related. If you’re looking for personalized help with English speaking or with business English, you can schedule a session with one of our amazing tutors today!

Jake Pool

Jake Pool

Jake Pool worked in the restaurant industry for over a decade and left to pursue his career as a writer and ESL teacher. In his time at Magoosh, he's worked with hundreds of students and has created content that's informed—and hopefully inspired!—ESL students all across the globe. Jake records audio for his articles to help students with pronunciation and comprehension as he also works as a voice-over artist who has been featured in commercials and on audiobooks. You can read his posts on the Magoosh blog and see his other work on his portfolio page at You can follow him on LinkedIn!
Share on facebook
Share on twitter
Share on linkedin
Share on reddit
Share on whatsapp